Did the RD-1 hurt Leica prices, or even Bessa prices, or keep Zeiss from bringin out the IKON? I know it isn't an apples to apples comparo, but I don't see people dumping their M5-M7s for the M*, unless they are seriuosly strapped for cash.
I think the bigger issues is, can Leica get new people into the RF world with this camera. If we just get incestuous marriages of film RFs for dRFs, that really doesn't grow the market. At $5000 (?) for the M8, I don't see people switching from dSLRs.
For the long term viability of dRF and RF in general, I think you have to make a better value proposition than the M8. We need a sub $2000 dRF, even if it is a generation behind in sensor technology. If a dRF can offer the compactness of an EVF with the image quality of a dSLR with out much of a price premium, that is the sweet spot.
Mark