I think Corona is a great kit for writing games in general, especially arcade games and board games. There’s no built-in support yet for tiled maps, and it looks like Cocos2D will have that built-in first. But even with that disadvantage, developing on Lua is so much more productive than developing on Objective-C that I’ll still come out ahead.

Some apps aren’t a good fit, though:

• those that extensively use the CocoaTouch UI controls. In Corona, you have to create your own buttons, text fields, etc. There’s the ui library, but it only covers a few controls.
• those that access APIs that aren’t wrapped yet by Corona. For example, access to the address book seems to be missing.

There’s the worry that Corona SDK will violate section 3.3.1. Folks from Corona gave some reassuring messages, but of course, with Apple, you can’t have absolute uncertainty. My take is that even if Apple gives Corona the boot, Corona will become Android-only, and Corona SDK is worth $99 even as an Android

I’m taking the $99 plunge. If nothing else, I think Lua will give me a refreshing break from my day-to-day Ruby and Javascript coding.