I'll take a whack at this, but this is just off the top of my head so your mileage may vary:
- Which states correspond to critical phases in your development process?
If moving a bug to state VERIFIED (for example) triggers a release to a client, then you should be darn sure the defects are actually fixed -- do you want to require an intermediate state (maybe FIXED) that anyone (any developer) can move bugs INTO but that only a QA analyst, project manager, whoever can move OUT of into 'VERIFIED'?
Ok that's all I can think of at this moment... anyone else?