After installing Perian and Movist (a video player software), I believe that I have solved most of the problems for mkv files in Leopard. I can play .mkv videos in either Quicktime or Movist, and I can tap the spacebar to quicklook the video when browsing in Finder. But one thing that I cannot change is that the thumbnails for these files remains a generic icon, unlike .mov files that have thumbnails of the screens of the movie. Thus when I'm browsing with cover flow, I can only quicklook the mkv files in pop-out window, rather than playing it in the upper part of Finder as what I can do with .mov or .avi files.
Is there anyway to improve this? I know Mac may not support .mkv files as good as .mov, so I'm wondering if there's any third party softwares that I can rely on to resolve this problem? I'll be grateful if somebody could shed some lights on this.