Interesting concept but I'm not sold that most customers are proactive enough to enroll (if they continue with this then I think it will ultimately become a benefit of being on a plan with Software Solutions versus a saleable add-on).
Hell - we could probably do the same thing if all fo the 90 Minds folks banded together and offered some type of monitored forum (similar to ask90minds) where support questions were answered to members who paid a fee (I would also dispute this at the same time pointing out that the average web visitor is looking for free and as soon as they see a $$ they'd move right along).