If you're already stuck with one, migrating to a supported one would be a good choice, at this point.
I have to concur with this line of thinking... while I do not believe a new SEO modification is required, I meant that as in NEW forum owners should do as fanyap said. Current forum owners looking to replace vBSEO due to lack of support/product updates due to the recent fiasco should more than likely take the easy way out which would be using a similar mod to retain their EXACT url structure and such, if however you have some experience and can remove the former and setup yourself properly then I recommend that instead.
So basically, for those removing vBSEO you will take a slight hit even if you cross all your t's and dot all your i's, you're still suffering slightly. If a new solution takes care of it all and seamlessly transitions you into a new SEO software from another without much fuss then I can't argue with that as it will help many non-seo familiar forum owners and save them much frustration.
Just don't go too crazy and end up mucking things up, SEO is great but dirty little tricks on top of plugins and such will only land you in a bad position or on the fifth page of search results .