It appears that Best Buy is currently having a special promotion on all MacBooks, Pros, Minis and iMacs (Plus Free Shipping). With savings up to $260 off, this might be a great time to consider a purchase.
The sale runs until the end of the week so it might be better to wait until after tomorrow morning to hit the buy button, at least where iMacs are concerned. Best buy also offers $20 Off Microsoft Office: Mac 2011 with Any Apple Computer.