I too considered buying EOS M before the price drop. I could not decide between it and NEX 5R. But then came the price drop and here we are. Why not get EOS M for S110 money.
I held out on the EOS-M deal until the last minute because I fancied NEX 6 or Fuji; but then again, those are not $299 including an f/2 lens. Another factor that pushed me to order the EOS-M was I found a third party EF to EF-M adapter for $45 that people have actually tried and proven to work well on EOS-M. I have a closet full of L glass and would hate to build up whole another set of lenses for a completely different system, not to mention all my EOS wireless triggers and speedlites.