They didn't become worse really. Houston and Phoenix just got better.
Houston picked up a great young PF who has fantastic per-minute production in Stromile Swift. He'll be dynamic next to Yao.
They've also picked up a great point guard, and no more of the human point guard by commite known as Mike James. As for Phoenix, there's no reason to believe Nash won't be his same MVP-calibre self, Marion will just now be enterting his prime, and Stoudemire will be a year further into his potentially dominating career. And to top it off, they picked up a legit PF, and got rid of the shot chucking Q Richardson. Not even Joe Johnson will be that missed, as he was so overrated, the veteran Jim Jackson will be able to fill his role easily.