Linux Mint 12 was released over the weekend (based on Ubuntu 11.10 "Oneiric"). The default desktop environment is Gnome 3 with MGSE (Mint Gnome Shell Extensions) -- a very nice alternative to Gnome 3 or Unity. This requires 3D graphics acceleration to run, and if acceleration is not detected, the LM12 runs in "fallback mode", which is a Gnome 3 environment scaled back to resemble Gnome 2.
LM12 runs in fallback mode in both Workstation 8.01 and Player 4.01, regardless of whether 3D acceleration is enabled for the virtual machine. Several people are reporting this in the Linux Mint forums (here and here). It seems that LM12 is somehow evaluating the detected graphics hardware at boot time, and something about the VMware environment fails the test. It should be noted that this failure is specific to VMware right now -- a VirtualBox VM with 3D acceleration enabled boots into the full G3+MGSE on the same host machine.
This issue can be easily duplicated by downloading the LM12 installation iso, and booting it within a newly created VM (with 3D acceleration enabled). The installer will boot into an environment with "Applications" and "Places" menus on the upper left, which is indicative of fallback mode. This can be confirmed by going to Applications->System Tools->System Settings->System Info->Graphics, where the graphics driver is listed as "Software Rasterizer", and the experience as "Fallback".
Any suggestions on workarounds, or steps to take to pinpoint the problem would be much appreciated!