Just didn't want to immediately go to using it unless we had no other option. s4 pointed out wbb to me originally and I thought it would be a good idea to use it and see if it would stand its ground under the stress of an off topic site. If we determine that wbb has too many bugs that go beyond justified reason, then we might plop down the cache. Some minor bugs which have already been found are expected in a free product, and are tolerable. When (and I do believe it will be a when instead of an if... that way, I won't be surprised about it) a major bug is found, I will either try to patch it up myself, or we may just have to dump this software and fork over more dough for vBulletin. That, unfortunately, may mean losing the posts, unless it is easily convertable over to the vBulletin database structure.
As for being a mod, there is a thread here about that. Go see it.