Define "building around".
"Building around" as in treating him like the best player on the team -- zero confidence in that. He may be great in setting up the table, and prone to the occasional stroke of defensive genius, but I don't see him as the type of guy who's going to carry the team on his back (and the post-Big3 teams will need some serious carrying).
Actually, I think that skill-wise, he's exactly the player you _don't_ build around: he's not a go-to scorer, he can't really shoot, and he can't make free throws. Rondo is someone you build _with_, the first player you want to add when you have that one legitimate building block.
That's not to say that you can't build around by keeping him and adding that legitimate #1; but if the right deal is out there, I'd move him.