you may wait for a mirrorless camera from Leica later, but it is at this time pure speculation if and when this will be on the market.
There are also some bodies (Ricoh, Sony, Fuji etc) that will give you the flexibility to youse your M-lenses as well as the R-Lenses.
And, as i said, in some situations, especially for landscape-photography, it works well on a M. You just need more time and atention for focussing.