This game has been heavily publicised and is released in a couple days but providing you order before 5:30pm today, you should receive it tomorrow morning via first class recorded delivery, as all orders are processed and dispatched the same day and arrives the next morning 99% of the time according to the site (which has always been my experience as well).
It's currently £3.50 cheaper than anywhere else and this is supposed to be one of the biggest releases on the PS3 yet, so it's a must buy and if you haven't already ordered it yet, you can't get it any quicker elsewhere.
Don't forget to go through Quidco to receive 4% cashback too, making this just £33.59 all inclusive.
Hope this helps. :)