Ubisoft has integrated GameWorks into Assassin's Creed Unity, or at least parts of it. The main feature to be included is NVIDIA's Horizon Based Ambient Occlusion Plus (HBAO+), which is their implementation of Ambient Occlusion. This effect darkens areas that would otherwise be incorrectly lit with our current limitations of Global Illumination. Basically, it analyzes the scene's geometry to subtract some of the influence of "ambient light" in places where it is an unrealistic approximation (particularly in small crevices). This is especially useful for overcast scenes, where direct sunlight does not overwhelm the contribution of scatters and bounces.
The other features to be included are Temporal Anti-alising (TXAA), Percentage-Closer Soft Shadows (PCSS), and GeometryWorks Advanced Tessellation. TXAA and PCSS were both included in Assassin's Creed IV: Black Flag, alongside the previously mentioned HBAO+, so it makes sense that Ubisoft continues to use what worked for them. GeometryWorks is a different story. NVIDIA seems to claim that it is like DirectX 11 tessellation, but is better suited for use alongside HBAO+ and PCSS.
Assassin's Creed Unity will be available on November 11th.