A few weeks ago, on our anniversary no less, I did this. As a surprise for Steffanie when she got home from the hospital, my family had came to the rescue and bought her a new 15.4" MacBook Pro. Monday night while she was in the NCCU, I turned on her old Mac along with her new Mac and using a spare Firewire 800 cable with Migration Assistant, I moved all of her data over to her new machine. It worked wonderfully. This was my first time using Migration Assistant, not ever having fully trusted it before, I usually manually copied over any data when moving to new machines. Everything worked great. Fast forwarding two days, Steff was home and using her MacBook Pro. She launched Twitterrific for the first time but the Mac App Store login prompt popped up. Not having ever logged into the MAS on this machine, it needed to verify her identity before allowing Twitterrific, a MAS purchased app, to launch. I wasn't aware it would do this, but it makes sense diving the DRM attached to these apps. It surprised me but I thought it was neat.