Yeah for music it's fine. You can drag and drop into iTunes (which I only learned recently) and can then drag and drop on to your iPod etc.
Photos have to be synced on PCs as far as I know--no iPhoto. Documents are a mixed bag. You can drag and drop into Goodreader and some other apps--but it really needs (at the very least) a central file location to drag any type of document and have apps be able to access rather than apps having to have their own file areas etc.
In any case, some are fine with the system. I'm not. I want a tablet that I can just plug in, have it show up like an external hard drive and then manage files, drag and drop etc. just like with an external HD.
So it's highly unlikely I'll ever get an iPad and will wait and see if any Android tablets fit that bill, or more likely wait until we there's a Windows 7 tablet with good battery life.
Playing around with my Girlfriend's iPad more, the novelty has worn off. I just don't need a media consumption tablet. I need a productivity tablet that works more like a PC, but can also do all the media consumption stuff. So I'll probably be waiting a couple years to get something that does all that, has a good UI, 8-10 hour battery life etc. But as I've said before tablets aren't a "got to have it now!" device for me, so I have no problems waiting.
In any case, I'll not post here so much anymore since I don't see myself ending up with an iPad and I think the device areas should be for owners and potential owners.