Installing Mavericks "broke" my Canon MG6120 MFP scanner and my Epson Artisan 810 plug-ins in Photoshop Elements 10. I was able to use Image Capture successfully with both, and I could also access and work the limited scan functions via the "Printers and Scanners" System Preferences - but I normally scan into Photoshop Elements. I haven't updated VueScan lately, so didn't try using it.
Both printers functioned fine as printers after the Mavericks install; it is only the scanner integration with Photoshop that was a problem. The Canon MFP did not show in the Photoshop Import options at all; and while the Epson MFP shows, it does not work there.
I was able to get the Mavericks-compatible scanner driver (with a TWAIN plug-in for Photoshop) for the MFP from the Canon site; after downloading and installing it, the Canon scanner once again showed in Photoshop Elements' Import function. The driver for that particular scanner can be downloaded athttp://www.usa.canon.com/cusa/support/consumer/printers_multifunction/pixma_mg_s eries/pixma_mg6120#DriversAndSoftware
I am pretty sure the drivers are there for most Canon MFPs and dedicated scanners as well. Get to the page for your particular scanner or MFP by entering the matrix here: http://www.usa.canon.com/cusa/support
One can also download the ICA and CUPS drivers from the support page. Having done that, Photoshop now once again shows the Canon scanner.
No luck so far for the Artisan 810. Epson says new drivers should be out "in a few days."
None of my efforts to get newer drivers via Software Update worked - including having trashed the two Epson printer files and trying again to download from Software udate, as suggested elsewhere in these forums.