Since Mac OS X doesn't officially support any scanners without the use of 3rd party software, I'd have to say none. For now I guess you are supposed to scan in 9.x (I don't think you can even scan in classic can you, I haven't tried) and then import the file (I assume twain or similar) for OCR. If you look carefully at the ad, they are very vocal about the ability to convert pdf files to readable text but there is little information about scanning in OS X. The manual is pretty silent on the subject too. My guess is that scanning is on the list for future OS X updates and the input scanned format will be pdf-like (to be compatible with document reader). If that's the case, Omni Page will be ready. My understanding is that Adobe is complaining that without scanning ability the functionality of Photoshop and similar programs will be limited. They even say as much on their OS X compatibility page. Still, I bought the upgrade and stand ready. Don't forget, Omni Page is also Mac OS 9.x compatible.
-Chet