My upgrade was due on the 17th (yesterday) but on Monday I visited the T-Mobile (UK) store and was told that the SGS2 wasn't yet available and wouldn't be for some week as it was being "tested" (read - loaded with T-Mobile guff).

So I got in touch with Chitter Chatter and they processed my upgrade there and then (

 

I'd never heard of them until I saw them mentioned here. Glad I found them as the deal is the same I would have expected from T-Mobile and the handset ought to be unbranded. Still waiting for any kind of confirmation of dispatch though.....

 

Still seems to be a UK stock problem on SGS2s - guy from Chitter Chatter rang me on Friday to say that they still had no stock and no idea when they are coming in.

Waiting.....