Diablo III may not have a release date yet, but you can start experimenting with your skill trees as Blizzard has posted a that allows you to choose six "active" skills, which are the abilities you manually use in combat.
You can then pick runestones that act as modifiers on each skill, allowing you to tailor your characters abilities much like you could tailor your socketed items in Diablo II. Crimson runestones, for example, make your timed skills last longer. Every player also gets a passive skill every 10 levels that puts a bonus on your stats.
You can then post your finished character to Facebook and/or Twitter to show it off. If that weren't enough, a Diablo III website which gives detailed info on each of the five classes in the game.is now on the official
This is ample evidence that a release date announcement is coming soon, so stay tuned.