Well, I can't say for sure Java Gaming is a "real" thing yet. But, it sure is getting there.
I know LibGDX will probably be a key player in the future of Java Gaming, especially if you find a cheap(er) solution for porting to iOS. I believe the moment that major Java games (Minecraft, Revenge of the Titans, Tribal Trouble, etc...) can hit every single platform, tablet, and phone; Java gaming will take off like a blazing rocket.
Hopefully, it won't hit any snags with that haunting "slow" stigma. Ugh... Java seriously needs a new school networked First Person Shooter that doesn't run slow to shut the masses up