The upgrade brings about a major change to how bugs are processed. The 'NEEDINFO' bug state was removed in Bz3.0.0. Instead the 'ASSIGNED' state should be used as shown in http://www.bugzilla.org/docs/3.0/html/lifecycle.html .
Whilst this might seem like an unintuitive change, Bz3 supports email correspondence. Hence if you need more information when working on a bug, indicate this to the bug reporter, set the bug state to ASSIGNED then submit. From that point on you can work with the user via email to resolve the problem.
All bugs previously in the the NEEDINFO state have now been reopened so feel free to assign any of them to yourself. Many of you will have received *lots* of email from this change, unfortunately it was unavoidable.
Finally if you notice any issues with the upgrade please let me know.