Sacado de Neogaf:
some of these might be part of the MS sale, I'll re-sort them later)
Renegade Ops - 800msp (was 1200)
Sega Bass Fishing - 400msp (was 800)
Wreckateer - 320msp (was 800)
Dirt 2 - 1600msp/20$ (was 2400/30$) US price, check your region
Nike+ Kinect Training
--Upper Body and Core Workout - 200msp (was 400)
Operation Flashpoint: Dragon Rising - 1200msp/15$ (was 1600/20$)
Overlord 2 - 1200msp/15$ (was 2000/25$) US price, check your region
Sniper: Ghost Warrior - 1200msp/15$ (was 2400/30$) US price, check your region
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Microsoft Studios Sale
A World of Keflings - 400msp (was 800)
Castle Crashers - 800msp (was 1200)
Deadlight - 600msp (was 1200)
Dust: An Elysian Tail - 600msp (was 1200)
Full House Poker - 400msp (was 800)
Guardian Heroes - 400msp (was 800)
Hydro Thunder Hurricane - 600msp (was 1200)
Hydrophobia - 200msp (was 400)
Pinball FX 2
--Marvel: Avengers Chronicles - 400msp (was 800)
--Pinball FX 1 Classics - 400msp (was 800)
--Plants Vs. Zombie table - 120msp (was 240)
Mark of the Ninja - 600msp (was 1200)
Trials Evolution - 800msp (was 1200)
--Origin of Pain - 200msp (was 400)
Trials HD - 400msp (was 800)
Forza Horizon - 3200msp/40$ (was 4800/60$) US price, check your region
Gears of War 3 - 1600msp/20$ (was 2400/30$) US price, check your region