I don't know how support is being defined here, but I have 20-30 WMA-lossless ripped CDs loaded and playing perfectly on my 8.1 1020; they've played since 8.0, always using only the stock XBM app. All have been ripped with Zune 4.8, and drag-and-dropped or copy-and-pasted from my PC to the 1020 in Windows Explorer.