[1] http://http.developer.nvidia.com/GPUGems3/gpugems3_ch25.html - https://github.com/hansent/lbfont is a good example
The Loop/Blinn work is really cool, and of course we now have hull shaders to really exploit it. It is a problem many people are actively working on...e.g. with Direct2D, but doing everything on the GPU is currently infeasible given round trip times between the CPU and GPU. Great if you can render everything in one pass, not so great if you can't.
Having said this, don't go turning this on everywhere, like on every tiny little UILabel. That GPU-accelerated CGContext is rendered in an offscreen pass using render-to-texture so it is often faster to use the CPU. This property was more designed for, say, a full-screen drawing app on a retina iPad that uses a a single screen-sized CGContext for its drawing canvas, or for the Safari case where there are a number of same-sized CGContext tiles to draw into.
> (e.g. Ejecta computes all bezier points on the CPU and just draws on the GPU)
I guess that's where the biggest gain comes from with NVIDIA: it's the only pure-GPU option right now, which probably eliminates quite a few bottlenecks. Freeing up the CPU is also never a bad thing.