If your mouse pointer is stuck in the lower right corner after upgrading to the current alpha version of Ubuntu, Intrepid, the reason is that the vmmouse driver got borked somewhere between Hardy and the current version of Intrepid. This means that you’ll only see “Moving to desktop 2” (or whatever desktop you have in the lower right corner). The fix is to change the reference to ‘vmmouse‘ in /etc/X11/xorg.conf to ‘mouse‘. This is not as good (you’ll not be able to move your mouse pointer from your host to your vmware machine seamless any longer), but at least it works.
You can track the current progress over at trackpad: Ubuntu Bug #248521.