Microsoft hopes to have 15 more Xbox Live Arcade titles available through Xbox 360 by the summer, according to IGN.

Speaking at this year's Games Developers Conference in San Jose, Microsoft reps also talked about what will happen as the service grows.

For instance, what happens when it gets crowded? Well, apparently the plan is that under-performing titles can be pulled if they're no longer exciting people - with provisions made so that people who bought them can always re-download them if they need to.

In development terms, games should not exceed 50MB - so that they can fit on a memory card, not just the hard disk. Apparently the goal is to get things down to 25MB so that you can stick two on the same card, although Microsoft expects sizes will increase too - particularly as more complex game engines like Unreal become available to Live Arcade developers.

Expect more stuff to pop up on Live Arcade for many months to come, then - including the much-heralded addition of Street Fighter II, which shouldn't be too far off now.