With the Maya Entertainment Creation Suite  2011 you still get Maya, MotionBuilder and Mudbox all under one license along with Maya Composite and Matchmove. While the last release was criticized by some as just being a bundling of software with seemingly slim improvements to the core software, Autodesk did not skimp this time around.
The latest release of the 2011 Autodesk products -- Maya, MotionBuilder and Mudbox -- gives us fresh new user interface updates and some killer productivity enhancements. For me, the biggest improvements are the improved workflow between the separate software using the latest update of FBX file format and lots of speed improvements to existing tools along with some big new features.
While I will not go in to every new feature in Maya 2011, let's start with the most visible. Maya got a totally new user interface using the QT platform, allowing for drag-able and dock-able windows, realizable splitters to adjust window size and a darker color scheme. Previously coding a custom user interface with MEL was limited and lacked a fast visual tool to design with, but using QT Designer you can quickly create complex tool Uis and even dock them right in to the main UI.
New to Maya 2011 is the Human IK retargeting solver, previously only available in MotionBuilder and as Game engine middle ware. This is great news for animators that are not able to always go to MotionBuilder in order to map or retarget animations between characters. For people new to the tool it can be a bit difficult to learn with the current UI but once you get past the learning curve and use it a few times, then you will be hooked.
On the scripting front, the script editor has been improved with syntax highlighting finely and auto-completes recognized commands and object path names if you enable the options. While python was introduced as a scripting option a while back, many users found it lacking and the guys at Luma Pictures  created PyMel to improve and speed up using python in Maya. Many technical artists wanted to use PyMel in their pipelines but couldn't do so easily because it was not installed as part of Maya and there were questions about support among other issues. Autodesk wisely took care of this by working closely with the creators of PyMel in order to both improve the PyMel project and to have it installed with Maya as a default.
Other improvements include being able to easily select and mask areas to paint weights directly within the paint weights tool. Previously users had to first exit, switch to component mode select verts and then relaunch the paint weights tool. The influence list has been vastly improved with sorting, filtering and pinning all speeding up the often times tedious task of weighting a complex skeleton. And Dual Quaternion skinning has been added to fix collapsing mesh points in areas like wrists and shoulders, along with the ability paint a mix map between regular linear skinning and DQ skinning, giving you needed control over the effect.
One other new skinning choice is the Interactive skinning tools that use capsules to quickly define how the skeleton will influence the mesh without relying on weight painting. Because the capsules are volumes the weighting information is not tied in to the vertx ID like regular skinning, allowing for changes to models without breaking all the weighting.
With MotionBuilder, realtime animation has always been its strong suit but they have somehow made it even faster for large scenes and heavy characters by utilizing the GPU for skinning and blendshapes.
The story tool, while faster with each past release, finished getting moved into the core display code and can now take on heavy edits with ease.
Materials and texture handling in FBX and Motionbuider2011 have been vastly improved. The update allows for more complicated shaders and per face texture map assignment to be supported. Having often had characters with 3dmax Multi-Sub Object shader on them, it was always difficult having to redo the texture just for export to Motionbuider, and now we don't have to, thanks to the latest FBX update.
While there are many other updates covered on the Autodesk site, the last thing I have to mention is that MotionBuilder now opens and saves directly the latest FBX format. Before MotionBuilder 2011, the FBX file saved out of Motionbuilder was different than what was exported from Maya or other FBX supporting applications and you were forced to keep track of exported FBX files separate from MotionBuilder FBX files. You also then had to use a separate importer to load them. This seems like a tiny thing, but after lots of confusion and frustration, it is now as easy as File Save, File open and I am very happy about that.
The 2011 version of Mudbox was not left behind in this update, getting powerful new texture brushes, posing and skeleton tools along with Hotkeys or Maya, 3ds Max  and Softimage  users to speed up ease of use. Also some review tools have been added allowing for quick turntable animations and high resolution screen recording for both sharing techniques and providing video feedback.
The new bone and posing tools that are going to be great for collaboration between character modelers and rigging. A low-res mesh can have a skeleton added and skinned up, then handed off to Mudbox and detailed out, allowing the modeler to test the mesh as it deforms and hopeful catch issues early on before final rigging has been done and animation begun.
For those that still want a bit more streamlined version or are using a mix of older software, the Mudwalker plug-in is still available from http://www.mudboxhub.com/ 
One of the exciting features for 2011 is vector displacement for creating images to use as stamps and stencils, allowing not only up and down values but also curves and bends like horns and other cool twisted shapes. This lets modelers create libraries of images that can recreate complex shapes on to new models as if you had sculpted them out of the surface from scratch.
While these new vector displacement maps are really cool, they can't be used outside of Mudbox2011 for rendering by default. Enter Wayne Robson again and his amazing and free Vector displacement shader for mental ray. You can download the shader at http://www.psychocore.com/ . There is a version for whatever application you have running mental ray  like Maya, Max or Softimage.
Maya Entertainment Creation Suite 2011 is a great set of software that is hard to beat when bundled together like this. While not all the tools are perfect yet, the amount of features and improvements are worth the upgrade. Just for the time saved in sending files between the software will cover the cost. As more and more features are shared between the Autodesk software, using the right tool for the job becomes almost transparent and just about all artists know how important being in the creative flow is. Now you can stay there while jumping almost seamlessly between software and working faster than ever.
Brad Clark teaches the art and science of character rigging and is a mentor and co-founder at www.RiggingDojo.com .