I load all my raw and jpg to dropbox so they are available on my iPad but no way I would consider loading directly to the limited memory of the iPad. It's a bit of a hassle when I want to show a client the photos because you have to wait for them to load. If you have a fast connection, no big deal. But it seems like everytime I want to show someone I end up on a slow connection. Even when it's a slow connection it only takes maybe 10 seconds to load so it's not a deal breaker...just an annoyance.
Still have not found anything useful to display raw (NEF, since I shoot nikon) on the iPad. Only reason for using RAW would be to edit so I just do that on the laptop and then save as jpg. The little Photoshop app in the iTunes store is not powerful enough to waste my time with RAW photos.
Nate