Currently, I don't have alot of experience with .classic, but I'm installing a copy to play around with to help answer some of the conversion issues/questions.
I don't think there will be a way to do a redirect to the actual post. Meaning, if you have a link in a search index to post # 323 in .classic, I don't think we'll be able to redirect to that post # in .threads. When doing the import there is no way we'll be able to keep the post #'s the same.
It should be fairly easy to modify ultimatebb.cgi to at least redirect all requests to it over to the main .threads page. I'll look into this shortly, in the meantime there may be some people who have already done this, that might be able to give some advice as well.
