Is there a way of reducing the number of triangles drawn by the terrain block or page? I tried using culling but I still get 20000+ triangles, and with the terrain page, it typically takes a long time to setup the terrain with culling enabled. I'm not too concerned with losing a bit of rendering quality.
Increase the step size and decrease the dimensions of the heightmap.
Also, you could render a smaller terrain size and stretch it.
also, you could wait for llama to post his terrain LOD classes 