How robust are your servers? Do you think you could handle a RaspberryPi.org blog entry?
Haha, I really doubt it. :-) But I dunno. It would be a good problem to have. :-P It's on Amazon EC2 and on a single instance of their smallest tier. But theoretically, it shouldn't be too hard to scale it up with EC2, since that's basically their core strength as a platform. It's a pretty simple app.
Er, I think berrybots.com could handle it. That site's pretty lightweight and on its own VPS. But playberrybots.com is on EC2 and obviously running matches server-side could slow down pretty quickly. Most matches only take 1-2s to run, so it should be able to handle at least a few people at a time.