Looked at KM planned launch of the wideangle, but it won't be out till Fall :(
So far, I saw there're Sigma 12-24, Tamron 11-18 that are available now.
And there're also 17-35 range by all Sigma, Tamron and KM but I think better to go all the way with the new Sigma/Tamron 18-200m - assuming...