They just started their holiday season sales. New deals every day between now and new years. Apparently there's also a twist this year which can lead to free games.
Servers overloaded / content not finished updating yet. Just give it some time to stabilize.
Step 1 for me: Pick up Portal 2 for 75% off ($7.99)
Intel i7 860, Asus P7P55D Pro, 4x2GB Corsair XMS3 1600 (CMX4GX3M2A1600C9), EVGA GTX 560 Ti Superclocked
Seagate 7200.7 160GB, WD Caviar Black 640GB, WD Caviar Green 1TB, WD Caviar Green 2TB
Dell 2408WFP and Dell 2407WFP-HC for dual-24" goodness