Oy, this is one of the most aggravating items on the backlog. We haven't had time to prioritize this yet, there's a lot of Destiny API features, bug fixes, and such that we've been prioritizing... but I do want to see us have full text search capability on the forums. I can't give an ETA on when this would come about, as we've got a mountain of work prioritized higher than that effort unfortunately. :(