Hey guys, didn't see this posted so I thought I'd do it.
Just called 2 HMV stores and they said this is indeed an offer for all high street stores (i.e. excluding airports etc.) and will run for the first week of the games release.
-Forza 4 included as well (Thanks Chaywa)
"Just checked my local HMV to make sure this deal was on and the edition they are going to be selling has a lenticular sleeve and you get a free t-shirt too. Makes the deal even sweeter." (via jcvanshazam)