Hey, guys, a little info from one of the Devs that I wanted to pass along:
1) Yes, there are three difficulty levels for campaign and skirmish, and it's not just about resource or stat modifiers. There are some limitations to what we can do with the iPad processor, but I think it should still present a bit of a challenge You can check out our AI's performance against other research teams at AIIDE07 http://skatgame.net/mburo/orts/AIIDE07/
2) Yes, there is both AI (three difficulty levels again) and multiplayer skirmish (3G, Wifi and Bluetooth). We've tried playing this against friends in LA while commuting by bus in Singapore-- because it's an RTS and less of a twitch game, latency problems are less pronounced when using 3G.
3) Yes, there is a 10 mission story campaign with unique objectives, like holdouts, covert missions, search and destroy, timing puzzles, straight buildups, etc to keep things interesting!
4) No level editor on the iPad yet, it is only available on PC. We're trying to figure out how to get it to players though, but it does require some processing to get the inkbrush style!
5) No IAP yet, unfortunately Lots of folks have asked though, so we should probably start working on this...