Just passing thoughts... I read the earlier post stating 9,000 names on the priority list, and realised it's probably more than that.
Seeing as Apple are only selling the iPhone unlocked in a few countries, the UK and France I think, a lot of foreign tourists will pop into the easiest Apple store to get an unlocked iPhone in the UK. Of course, that'd be the one on Regent Street.
This could work both ways... a lot of people won't be able to pick up their reservation as they'll have left the country so the list could shorten quite quickly, but it also means the Regent Street store is always going to have the largest priority list by a long way.
So, if you're still after an unlocked iPhone and are not on any priority list, go to the other Apple stores to put your name down, and although there's no guarantee you'll get one quicker, I'm sure the list will be smaller in the stores harder to get to for visitors.
Of course, I say this as one of those 9,000 names waiting for my unlocked iPhone and I'm now just waiting patiently for that email to pop up (undoubtedly when I'm out of the country on holiday!).