Touch Arcade has a nice interview up with David Frampton, author of both the Mac game Chopper and its upcoming port to the iPhone. Apparently the game is feature complete and now in testing, so hopefully it'll be one of the first apps up on the App Store when it arrives, supposedly sometime this month.
The game will use the iPhone's accelerometer to control the little helicopter, and Frampton says it's both a blessing and a curse, in that it makes things more fun to control, but the iPhone also has to be held at a certain angle to center it out (they're planning to get around this by adding a way to calibrate it for different playing situations). He also talks about how the iPhone's OpenGL ES version works, and says that, despite our worries about battery life, the iPhone is able to churn out a pretty consistent FPS as well as keeping battery usage fairly low. To be fair, Chopper is probably on the low end of graphics potential, but we'll take any good news we can get here.
The game is still on track for a release in late June, and while even Frampton doesn't have details to share about the App Store's launch day, Apple's past support of this title means that if any third party games make it into the App Store, this one will definitely be there as early as possible.