Got this today from a new source. Canon will release a firmware update for the Canon EOS M before Christmas. The new firmware release is said to address the auto focus problems, mainly the sluggish focus time, of the EOS M, both for the native lenses and for EF and EF-S lenses used through the EF/EF-S adpater.
I really hope this rumor is going to be true, although I didn't so far experience any major drawback with the AF. See my first impressions of the Canon EOS M here.