good question. Here's some more:
what app(s) are you guys using on your iPads for your char sheets?
To what end will passing info to your GM be useful?
Would MapTool's chat/char management work on the iPad (the web version?)
I just got an iPad. Haven't gamed with it. yet.
Being a software dev, and a gamer, I look at the problem differently.
pre-iPad, the problem I saw with most character software, like PC-Gen, was that it was oriented towards making a PC, or managing between sessions. i hadn't found an app for PLAYING the game with the program acting as a faster than paper character sheet.
In the end, a spreadsheet I made was more effective (and faster to design). It actually worked fine during the game (each sheet held an aspect of the PC), but leveling up meant more spreadsheet modification to make it auto-add things or have hyperlinks to d20srd.com. Stuff that real software could handle well.
If you haven't solved the problem of holding my char sheet data AND making it easy to play the game AND update my character, then passing data to the GM isn't a priority feature. Hence why I'm curious as to what your using.
Passing data to the GM also couples into what app your running, and what app he's running. In theory, the GM really needs a PC, if he's running the whole game from a computing device. He's got more balls to juggle.
In which case, MapTools (if the web version works on the iPad) may be sufficient. MapTools is part of RPTools, which includes the chat client and PC management system. Turn off the map on your iPad, and use the chat and PC management part to hold your PC, track your HP, and send secret messages to the GM.
I'm not sure how feasible that is (like I said, I haven't tried it). You could also consider using an IM tool (like MSN Messenger) to send the secret messages.
To me, the inter-linking and passing data is just extra gravy. You didn't need it before when you had paper. Replacing paper with the iPad is the first problem to solve. Once that's solved, your app has all your PC data to be able to send to a central point (the GM), so only then is it worthwhile to pursue that technology.
And the trick with that is you need to invest in a total platform. You can't easily bridge disparate apps on the iPad, let alone to the GMs computer that doesn't link to those iPad apps.
Back in the IRC days, I used mIRC and some scripts I wrote to hold my PC's combat stats (AC, total HP, current HP, weapon stats) and it would recognize what I typed or the GM typed as commands to alter my HP, display my curent stats and make attack rolls. That was sufficient for online gaming with a char sheet next to me.
Merging those concepts, an app that holds the char sheet AND talks to others via a chat client and can pass commands via the chat would solve the problem. From what I can tell RPTools does that, though I'm not sure how well or easy to use it is.
i bet there is not an iPad app that does that. Let alone, one that truly acts as a char sheet that is easy to use as well as supports your chosen ruleset.
