Doesn't Zoho do pretty much everything?
I'm not familiar with Filemaker Pro, though.
My main problem would be if the screen is big enough for full JPG text-book pages, and if the zoom is efficient enough to warrant use of a small screen. I guess zooming might be a problem for you, too.
I'm trying to replace text books with iPod Touches. 'Cause my backpack is 30 pounds, and the maximum doctor-recommended weight you should carry on your back is about 15 pounds.
I hate integrated apps; I don't want my friends who are active on Pownce and Twitter to see the same message posted on both. That'd be stupid. I say it'd be better for each person to just choose which they like the best and stick with it.