Is it possible to use the Migration Set-up Assistant from 2 other Macs to talk to the Macbook Pro too? I want to copy some apps. If they are apps I have bought, will they just transfer over or will I have to get another registration number or pay out more money to put it onto my new computer?
The answer depends upon how the developer set up the apps. When I migrated from my G4 to my Mac Pro, Photoshop asked (the first time that I launched it) if I wanted to transfer the registration to the new computer. I clicked Yes and was done with it (no extra licensing fees involved). No other app did this. At the time, I had Office X installed and there was no issue with that. Since Adobe and Microsoft are probably the most vigilant (read paranoid) companies about licensing, there may not be any other problems.
That said, the license agreements for each app may have different requirements so you may have to buy new licenses, even if nothing is said (don't ask, don't tell?) in order to be legal.
About Office X: The transfer was completely legal because I erased the drive on the G4 after migrating, thus removing any unauthorized copies.