I agree. We can't even do basic keyboard input at the moment or recreate the graphics screen in real time. I don't think shaders should be at the top of the "to do" list right now...
Mark didn't say that was his priority. I get the impression that is is switching between this and probably spending most of his time on the Compiler / Debugger / Bug Fixes. However a worklog about the 3D stuff is obviously a lot more interesting.