It should come as no surprise that both Palm webOS and Google Android want iPhone developers on their platform. Mac developers have long been as passionate about their platform and incredibly talented in the apps they've delivered, and a lot of that has transferred over to iOS devices like the iPhone and now iPad.
Whether or not Apple is engaged in a platform war with Palm and Google it's inarguable that the current generation of users want apps and right now Apple has an advantage in that area. Part of getting people to switch to another platform is making sure the apps they love are on that platform, and that means big name apps and fan favorites alike.
If Google is moving around behind the scenes, approaching core iPhone developers (the ones who make the most iPhone-like apps and enjoy high mind share) and trying to sneak them over to Android, Palm has gone one step further -- openly courting them.
In the middle of Apple's iOS-centric WWDC 2010 no less, Palm held a shindig of their own, a PDK (Plugin Developer Kit) soiree to wine and dine iPhone developers, point out the Pre has pretty much the same guts as the iPhone 3GS, and that a lot of applications can be ported over -- especially games. And they made certain to highlight their openness, especially to emulators and cross-compilers. And they offered $1 million dollars in incentives.
Obviously users go where the apps are and developers make apps for where the users are, so the cycle can be vicious or virtuous, and just as obviously Google and Palm would much rather the latter.
Competition is good, different approaches are good, and options for developers are great, but whether or not Google and Palm can convince iPhone developers (and now iOS 4 developers) to become mobile developers is the question.