Ever since he was first introduced, Stuart has been an interesting character. Kevin Sussman manages to make the character neurotic and self-effacing, but he at least had some success. He was able to get the best of the guys by manipulating them into buying things they didnt need, had his own store and even asked Penny out. Everyone complained about his downfall but at least things are looking up for him now. Being in a relationship with Howards mum will give a great opportunity for good comedy, and you've already seen the beginnings of that with his exchanges with Howard about not being his dad. It will also let the show do a bit more that the surface humour thats been prevalent recently. Investigating an older woman having a relationship with a younger man and societys reaction to that will let the writers use comedy for whats its supposed to be for; challenging ideas. As well as having Stuart and Howard continue the more base whos your daddy jokes of course. Getting the comic book store back up and running and really making a success of himself could be just the role model that Howard needs. Stuart is a great character, he has plenty of scope for growth and he doesnt need to be the butt of jokes to be funny.