For a cheap headset? What, were you only 98% IN before?
The headset is a big part of the experience. Having to spend $25 on launch to get a new one would basically mean one less game for me (I'm planning on picking 2).
It may not be all that, but the 360 one held up pretty well, and seems to be a better one than Sony's including. I'm sure I'll eventually buy a wireless one, but for launch, every penny counts.