With the pie menus, new for blender 2.72, I'm now wondering how do I get to them? I have tried some of the different keyboard shortcuts mentioned for the pie menus.
For 2.72 you have to enable the pie menus in the user preferences. CtrlAltU or
File -> User preferences then the Addons tab. Search for
pie, enable the addon called
User Interface: Pie Menus Offical.
After the pie menu addon is enabled the keyboard shortcuts such as Tab or Z will open a pie menu. Documentation about the pie menus on the blender wiki.