Excellent news. My last Mac migration was performed using Carbon Copy Cloner, which mostly worked, but needed a little geekly intervention to finalize. Being able to buy a new Mac, firewire it to your old one and migrate the accounts and settings you want will go a long way towards keeping folks on a regular system upgrade path.
Now if Apple made a similar tool to hook an old PC to a Mac, move over everything (except the viruses/spyware/adware), I think they'd be on to something. New Macs already come with a 30 day Microsoft Office for Mac demo so, presumably, a PC user could be up and running on a new Mac the very same day. The one-wire OS upgrade...I like it.
Now why would PC users want to give up their viruses/spyware/adware?