i Have a link to a forum with a list of deals over the days and so far it is correct so here are the lists and prices.
20th, new year theme free
21th, Lips DLC previously 180 points now 80 points (white christmas)
22th, LIVE Arcade Rez HD, 800 -> 400
23th, LIVE Arcade MARVEL VS. CAPCOM 2, 1200 -> 560
24th, LIVE Arcade, UNO Rush 800 -> 400
25th, LIVE Arcade, The Secret of Monkey Island 800 -> 400
26th, LIVE Arcade, Magic:The Gathering 800 -> 400
27th, Fallout® 3 DLC 400
28th, Guitar Hero 5 Rolling Stones Live Track Pack 720 -> 320
29th, LIVE Arcade, Braid, 1200 -> 560
30th, LIVE Arcade, Castle Crashers, 1200 -> 560
31th, LIVE Arcade, Battlefield 1943, 800 -> 400
all week shadow complex 800msp
Lastly i still picked up worms 2 for 400msp even tho apparently it has ended.
Edit by Eldini:
Some of these deals are only available in foreign territories, but so far half of them have been available in the UK.