I am basing my expectations on the pricing on XBox Live. The XBLA stuff fluctuates and there's been a couple of sales (got El Shaddai for ~2$ so I know it's non-zero), but mostly everything stays pretty high relative to what the market can bear. If they change behavior, so be it, but let the record show it's not groundless speculation; the digital download market for Xbox 360 has been around a while.