Based on NPD sources and some calculations, Gamasutra narrowed down the Wii U sales estimates for January to be roughly between 45,000 and 59,000 units. That's a fairly pultry number and it's doubtful we are going to see any growth on that front in February. According to data at VGchartz, it sold roughly 67,161 units, but their numbers are not exact since it accounts for weekly sales. The first week for January includes some days in December, and the last week of recorded data for January is missing the last days of the month.
Either way, sales are low, and based on early data for February, they will likely be even lower this month. Now logically, you can place some of this blame on the lack of content since the holidays and the usual holiday drop off. You could also safely say many consumers aren't product aware yet (again, without software to consistently show off that happens), and I know some feel the Wii U is a bit pricey even though it's being sold at a loss. Certainly sales aren't doing hot, but it does appear they have steadied themselves for now. The question becomes: will new compelling software in the coming months boost the sales again?