I'm using Parallels for Mac and VMware Fusion (on a Mac, obviously), and I'm using Ubuntu 12.04 as a guest OS. The tablet I'm using is a Wacom Bamboo Pen & Touch (CTH-460) and it's my only mouse device.
The touch part works reasonably (although the cursor moves a LOT quicker under the Ubuntu guest OS), but the Pen part doesn't work properly at all. I can hover the pen above the tablet to move the cursor ok, but if I tap the pen on the tablet the Ubuntu guest OS will register a click and a drag to a random position on the screen.
It happens the same on both VMware Fusion 4 and Parallels 7 (both with their own installation of the Ubuntu). If I force the USB device to connect to the guest OS I lose the usage of it in Mac OSX but then the tablet works fine under Ubuntu.
I can't decide if this is an issue with Ubuntu handling the 'fake' HID or the VM software doing something strange, but a Windows guest works fine with it.