Judging by their use of chameleon, and their general UI choices, I think we can expect an iOS client from github as well in the future (using the same codebase as this desktop version). I think that OSX + iOS > Windows users in that regard.
In respect to the Windows question, I wouldn't be surprised to see them ship one in a few months, once they iron out the bugs and determine exactly which set of features a native client needs to provide.
Everyone's all cuckoo about Chameleon because it lets you port iPhone apps — but the real win is a fully layer-backed environment with modern APIs (UIKit).
Our decision to use it has nothing to do with iOS at all.