Following the recent aquisition of a 105/2.5, and a very enjoyable walk in the spring sunshine at the weekend, I think I can safely say my two-lens kit is this and a 24/2.8. Three lens, and a 50/1.8 is added. Really lightweight will be the 50/1.8 on its own.
After looking at what I've actually used from my lens collection in the last year, I will shortly be selling a 15mm fisheye (done the gimmicky shots to death), 80-200 f/2.8 (fantastic lens, really like it, but too big and heavy so I hardly ever take it with me), 35/2.8 (just not a focal length that suits me) and possibly 28/2.8 (might keep hold of this though, for when the 24 looks a bit extreme).
Some of the money raised will go on a 50/1.4 or 1.2, or a 55/1.2 to extend my low light capability.