Sure do! Accounts created then will not be upgraded. Once activated, those accounts can be used on the forums. When logged in a not-upgraded account can be upgraded with PayPal for $5 (US).
I put the system in place a very long time ago in the hopes that accounts would be created faster than this I recall it being well-tested, but when it gets closer to the limit I'll probably look over the code again to be sure.
I've been playing a lot of KarBOOM 0.3 with my youngest brother (unfortunately he's better than me at it). Still a way to go, but most of the gameplay stuff is implemented.