There has been an unofficial XBMC for android released for quite some time. XBMC For Android | XBMC
I have it on my tablet. Works fine for DVD quality streaming over local network. Don't have local Hi-Def mkv files, so can't test those. But those stutter over the network.
As for loading those on the media players, I don't think those will work well. All the decoding, processing etc is done in the software so it will be very slow. Unless someone makes an XBMC port which will do hardware decoding and processing specific to these SoC.