But a big part of this issue is the upcoming Mac App Store. The rule that's been floated is apps cannot be based on "deprecated or optionally-installed technologies". This makes a lot of sense, dependency hell and all the other related things proprietary platforms do so poorly (I'm looking at you, Microsoft) are seriously improved with such a rule. Just think of the lower number of trouble tickets and irritated customers.
Straight from the source means ... ta-da! "Optionally installed". Therefore, no Java-based apps in the Mac App Store.
Bad for Java app developers on the Mac - Apple's app store is likely to be a very good channel for sales - unless Oracle step up to the plate with a (cross-platform) app store. But good luck with that - it won't be so visible, cross-platform apps are generally dodgy, and it doesn't have Steve Job's magic pixie dust.