At least we think alike:
They could still sign Wolf, but it appears increasingly unlikely now with the bargain-basement $2-million signing of Mike Hampton.
I'm guessing they decided it would be dumb to trade Jose Valverde, and that they'd rather take their chances with Hampton if it meant they could keep the National League saves leader.
Maybe the Astros took a deep breath sometime in the last few days and decided they'd rather have Valverde than Wolf. That's an interesting decision.