I don't want to hijack your thread, but I too am looking for a new scanner/AIO and my requirements are similar to yours.
The main thing I am looking for is better network scanning.
With the Canon MX860 I can already scan to iPad with
Vuescan, but it's cumbersome and what I really want to do is scan to my NAS or dropbox/Google Drive or even to e-mail.
The MX860 worked great up to OS X 10.6, I'd scan to an SD card in the printer and pick it up over SMB. 10.7 broke this and the printer crashes when I retrieve a file. Works fine from my lone Windows box though...
B