Can You Stop the Migration Assistant Midway Through? Can the Migration Assistant be stopped midway through? I began the wireless transfer from a Mac Mini to a new MacBook Air last night. It still says it's going to take 40 hours. Unfortunately, I can't wait that long, and the process is taking up both of my computers. 

In case of catastrophic failure what recourse do I have, as the MacBook Air doesn't have a system restore disk?
Pressing Command + Q on both machines will exit the migration assistant.

I have a feeling that it copies all files to temporary location before installing them/creating user accounts. So you should be fine. Depending on how far in you might have problems.