The Steam like service Desura now has a linux client (in beta currently) in addition to the Windows client, making it one of the first such games portal style digital distribution services for Linux.
This makes it ideal target for Java games (in fact one the most popular games on there now is Project Zomboid (a Java/LWJGL Game).
From what i’ve heard they are making some pretty nice deals with developers as its still early days for the service.
Announcement can be found here.