Not before time NVIDIA have
NVIDIA have also taken the step of calling these drivers 'Game Ready', their own reference for a driver most suited for day-one installation and use. As such it's likely to be recommended for the Windows 10 RTM (the OS still being in a testing phase right now) as well as initial benchmarking for the new OS with NVIDIA GPUs.
Unsurprisingly the GeForce 352.84 WHQL offers full compliance to WDDM 2.0 specification, and offers support for DirectX 12 on GPUs with Maxwell or Kepler architectures. Older 'Fermi' (i.e. 400- and 500-series) GPUs will support DX12 in a future revision.
Whilst there are no DirectX 12 games currently available NVIDIA does suggest a cadre of tech demos to stretch your GPU and observe some of the benefits of the new API. Forza DX12, Fable Legends DX12, WITCH CHAPTER 0 [cry] DX12, King of Wushu DX12, and Unreal Engine Race DX12 are all tools which NVIDIA have showcased new game engines using elements of DX12 on NVIDIA hardware.
NVIDIA's Desktop GeForce 352.84 WHQL drivers for Windows 10 can be downloaded here. Laptop drivers can be found here. This is the most current and stable driver listed, but the 'in development' nature of Windows 10 could still cause instability on some systems... such is the nature of a beta environment.