Yep. GB is x360 land.
Don't forget however that x360 has been on the market here longer (about a year I think) than the PS3 so does have an advantage.
Where the x360 was at after five years will give a more direct comparison.
The way I see, although basic, is it's x360 (usa, uk - the biggest markets) vs PS3 (the rest of the world). The future is interesting regarding this battle.
Well it's interesting, because a year ago the 360 was at 6.7 m and the PS3 was at 4.2m. what was that guy saying about momentum again?
The 360 install base is up 1.3m (19%) in a year and PS3 up 0.8m (19%) in a year. So momentum is identical (but on a larger starting point for the 360) and the 360 will continue to stretch the lead.