While I certainly can't vouch for this problem myself as I don't own a MacBook Pro, there seem to be quite a few owners of the new laptop with complaints over a high pitched noise emanating from their machines. Our own Dan Pourhadi had a whine on his new MacBook Pro, even though it may not be the whine being heavily discussed on Digg today. Dan seems to have solved his whine by disabling the second core of his processor (described in Update 3 on his post).
I no longer see this thread Digg links to on the Apple Forums, however I did find another active thread about the high pitched squeal/noise/whining. Some Apple users on the Digg thread and the Apple Discussions thread seem to think this may be repairable in firmware by Apple at a later date.
I am by no means dissing Apple (or the Digg crowd) with this post, but simply would like to remind everyone about early adopter syndrome. The first revision of a new hardware platform or change in manufacturing is bound to engender certain flaws or bugs. Please, let us reflect for a moment on the Mirrored Door G4 and the PowerBook 667MHz (aka The "666") computer lines.
This current flare in comments on Digg and the Apple Forums doesn't mean that all MacBook Pros will be affected by this noise, and certainly does not mean that people shouldn't be entitled to a worry-free machine when purchasing a Mac. I hope this all gets cleared up quickly and with some sort of patch or replacement from Apple. We at TUAW are bound to keep you posted.
Update: Please see Dan Pourhadi's new follow-up post about his MacBook Pro woes.