Using mod tools make this kind of list easier to make. Anyway, for February, here is the break-down of where questions were migrated away from ServerFault. I didn't go into any additional stats (mod-hammer vs. vote-to-5) or what happened when they got to the destination site since I'm on a crap network and that kind of loading may just kill it.

Destination   | Count
------------------------
StackOverflow | 14
SuperUser     | 133
Meta.SF       | 1
WebMasters    | 40
------------------------
Mod-moves to any site:
------------------------
AskUbuntu     | 5
Apple         | 3
WordPress     | 2   
Unix & Linux  | 8
WebApps       | 2
Security      | 1 

209 migrated questions, of which 63.6% went to SuperUser. What's interesting to see is that migrations to WebMasters outnumber migrations to StackOverflow.

Moderators do have the ability to move questions to other sites, and 10% of 'em have been. If a question is a generic Linux question (example) that has to do with the inner workings of Linux and doesn't directly touch on sysadminly or end-usery things, mod-flag as a migrate to Unix & Linux. As you can see, we get a fair number of those. SuperUser-style questions regarding Ubuntu may be a better fit for AskUbuntu, although that question hasn't been fully resolved to my knowledge.