I'd kinda put the Wii U sales in these categories
Sub-200k - System was always dead, you just didn't know it, like Bruce Willis in The Sixth Sense.
200-250k - Disastrous
250-299k - Very Poor
300k-350k - Bad, But All Things Considered ...
350-400k - Decent
400k-450k - Getting Into GameCube Territory, Not Bad.
500k+ - Good month, a solid rebound looks to be in effect.