I agree on the issue of holding the R lenses until the R10 is on the market. First because if you choose to get an R10 that won't be the time to be buying R glass because it is likely to have skyrocketed. If you decide not to buy an R10 you can then sell the R glass at a much higher price! Win Win as they say.
I have sold some of my R glass such as the superb 35-70 Elmarit but only because I had two copies! So my current lineup is 15 Elmarit (which I also use with an adapter on my M8), 19,21-35, 35-70 Elmarit, 90 cron, 100 Macro, 180 Elmarit APO, and 280 4.0. Along with the 1.4x Extender this is a pretty formidable lineup.
So bring on the R10
Woody