aïe
après recherche rapide sur le net, les nouvelles ne semblent pas excellentes: pas de driver compatibles Mountain Lion !
MAIS
ai trouvé cela, un peu de bidouilles mais ça semble être la seule solution:
Success!! I got my LIDE 35 working on Mountain Lion 10.8.2. It was pretty easy - despite the information posted on the Canon website (that no driver is required for ML), I downloaded the Canon driver for Snow Leopard. The file is named lide35osx7721en.dmg. I got it here:
http://www.usa.canon.com/nw3s/CanonUSA/DownloadContents/English/0900320002EN.htm
Ran the Canon installer, rebooted, and everything's good. Scanner seems to work fine, using Image Capture for the scans. I did not download/install the CanoScan Toolbox. I'm happy using Image Capture and Preview for scanning, and I might acquire VueScan as it gets pretty good reviews. Frankly, I'm a little leery about installing Canon's Toolbox. It needs to actively monitor the status of the scanner, watch for the front-panel buttons being pushed, etc. It's plausible it might not play nice with ML.
Based on the info posted in that other thread about the LIDE 60, you might need to uninstall your exisiting LIDE35 s/w before you can re-install. For reference, that article by "7p" is here:
https://discussions.apple.com/thread/3192066
However, it contains an error. Steps 1-4 direct user to remove a Canoscan file from within the user's ~/Library folder. In fact, I believe you'll find the file is in the root Library folder. After running the installer, I went looking to see what had been installed.
/Library/Image Capture/Twain Data Sources/CanoScan LiDE 35.ds
/Users/Shared/CanoScanLiDE35/CNQL1208_Driver.bundle
The actual driver file is contained within the bundle, and is dated June 2006!