Why is Apple Announcing Hardware Upgrades Before Macworld Expo?

Apple went ahead and announced an upgraded Mac Pro and an upgraded Xserve this morning. These announcements occurred one day after Intel announed 16 new processors based on 45nm silicon fabrication at CES.

I'm a bit confused by the timing of these announcements. It makes sense to release these new machines to the world as soon as possible since both the Mac Pro and the Xserve haven't been significantly upgraded in more than a year. But, why do this in advance of Macworld Expo? Is Steve Jobs going to have so much to demonstrate that these announcements couldn't be worked into his keynote?