It really comes down to how Apple wants to go with this. I see three distinct possibilities here.
-1 they really don't care when Macworld takes place one way or the other any more, which is how they have characterized it
-2 they DO care from the perspective that they could get a nice bump in sales by selling 'to the faithful' who are already gathered and once a few of em buy the gear pre show, showing it off to the others gathered there make them go viral. Assuming there is something serious to show besides just moar megahurtzes. Like Bluray for example. =)
-3 they want to stay out of the Macworld Limelight alltogether and wait until the show is over on purpose (spitefully or not) to have the virtual stage all to themselves.
Which of the three do you see as the most Apple-ey? I say, sadly, #3. Remember iLife needs an update too. Is the time to launch iLife 10 now or is waiting all the way to WWDC the right thing to do, or if you are Apple do you have another special event prior to WWDC to do existing platform refreshes? If that's your strategy you really need to have some tricks up your sleeve. Anyone who thinks that WWDC will see a return to focusing on OSX for desktops instead of it being an iPhone / iPad Rah-rah session hasn't been paying attention to the last 4 years...
Sam
Edit: more rumors!
http://www.businessinsider.com/apple-to-upgrade-macbook-pros-tomorrow-ahead-of-macworld-conference-2010-2Edited by Sam Posten - 2/8/10 at 12:37pm