Why would we?
Ty is pretty much untouchable, unless we get a star in return. And not a chance to deal with division rivals. I really like Rudy Fernandez, I'm sure our team likes him too, but not even if he's included, would we do that deal. I believe Ty is that important to this team.
Think about this, when he's on the floor, all of a sudden, he makes our bigs (not named Nene) a threat offensively. We really relied heavily on Nene for post production, but now with Ty's speed to break down and draw defense and passes either off pick and roll or double team, guys like KMart (especially him) are going to finish around the rim easier. It really takes load off Nene's shoulder...
He also actually plays very good defense, I've been impressed throughout pre-season, Jazz and last night's game with his quick footwork to stay in front of his man. I thought he defended Rudy very well, contested his shot the best anyone his size can, and I thought his defense is pretty good, but Rudy just knocked down tough shots. Karl is going to realize the rookie actually plays good defense on Rudy when he watches tape, only happened Rudy knocked down tough shots and made it look like "he burned the rook". The only real problem (and I don't really think it is a problem) with his defense is when a strong guard like Deron Williams takes him to the post and score. But Ty is strong himself, he's gonna watch tape and figure out how to do better defensively, maybe draw a charge, etc.
Why would we give him up? His speed makes 2-3 guys pretty much irrelevant on offense to relevant, he is a Yang to Billups' slow Yin, his game gives us a different dimension on the offensive end.