I do not see this listed anywhere as a limitation so I thought I'd post it. If I just could not find it, maybe you could point me to the documentation - otherwise, I just wanted to make sure this was recorded.
When working in NURBS; the "Display Render Tesselation" option returns incorrect values in Viewport 2.0; the tesselation shown only relates to the "1", "2" or "3" key rather than the actual settings.
Changing the default hardware renderer to the Legacy renderer will show correct tesselation on NURBS surfaces.