Shameless self promotion: I offer free hosting for Java, Processing, and Android games at http://StaticVoidGames.com
. It's still a work in progress, but I'm constantly working on upgrades and new features. You can even specify your own ads, so you can keep 100% of the revenue your game generates.
And I'm using Amazon web services behind the scenes, so scalability shouldn't be an issue.
My hope is to create a community of Java developers, tutorials, and (optionally) open source games, but for now it's at least an easy way to host Java games.