OpenJDK will have a native Mac Gui
Apple are donating their current Java code base and tools, including the graphical bindings, so you can expect OpenJDK 7 to not look too out of place on the Mac, see:
@Niall - As much as I like Apple products, you're right on the anti-competitive point. Basically, Google Android is taking Apple market share, and Apple doesn't want to help you learn Android's programming language, which is [mainly] Java.
This strategy has been good for them financially until now. Having to learn Objective-c/XCode/Interface Builder weeds out the weak, so there's a bigger share of dev dollars. However long term, I'm not sure this will cut the mustard. Devs will want to target as big a market as possible, so cross-platform is probably where App dev is heading (see Monotouch, Mosync, Airplay, Unity etc. etc.).
That's my 2p.