As Cruiser says, you won't have to re-register or any of that. In the final release (and probably for some of the later betas, so it can be tested,) they'll provide an upgrade path. I reckon you're best upgrading after the first 2 or 3 security/stability releases (not before, as only so may people will test the betas and release candidates, and this is a BIG forum) (not after either, phpbb3 is going to be far more awesome than 2, and eventually they'll stop maintaining the 2.x branch and people will discover vulnerabilities (every piece of software more complex than hello world has vulnerabilities) and yeah, very unwise to use.) Advantages/reasons for upgrading: http://area51.phpbb.com/docs/features.html I can see plenty of great things in there :)