Multi touch is fixable as well on the Trackpad. When 8 is installed there will be 2 drivers for the Trackapd with exclamation marks. Right click and choose update driver. Select to browse rather than search and then Let Me Pick.
Select HID Input device. Repeat this on the second broken driver. Then right click and update and it will correctly install the Apple Multi Touch device correctly, repeat this again and restart and the Trackpad will work fine.
I'd also recommend downloading Powerplan Assistant and then Trackpad++ as this will add Windows 8 specific gestures.