Take your scanner into an authorized service center that has Snow Leopard installed on their machine and ask them to help you to see if it might be compatible.
The best purchase that I've ever made was to buy VueScan Pro and not have to worry about scanner drivers ever again. It is SL ready and will support your scanner and is constantly updated for new scanners.
Since this thread is specifically about the Canoscan 8800F under Snow Leopard, recommending Vuescan Pro when Vuescan Pro requires the Cannon drivers installed for the 8800F is bad advice. The Cannon drivers will not be available for a few weeks according to the Cannon support site..
Interestingly, also, the drivers for 10.5 have very recent creation dates (7/29/2009), though they appear to be the same drivers that have been available since at least December, 2007.
I have a Canoscan 8800F. Just upgraded to Snow Leopard. The scanner works fine, with no special action required, both with MP Navigator Ex and Preview.
For those who've prematurely upgraded to Snow Leopard and found their scanner requires updated drivers not yet available, there is Apple's +Image Capture+ app in the Applications folder. Some scanners will work with this without the need for the manufacturer's software drivers. Read more in this Apple doc:
...And for those who haven't yet upgraded to Snow Leopard and prefer not to wait for updated drivers, if +Image Capture+ works with your scanner and current version of OS X, it's likely to also work in Snow Leopard.
It doesn't work under Snow Leopard in the current form I have installed. PS CS4 crashes outright. When I try it in PS CS3, the beach just keeps spinning until you Force Quit.