There's another thread around here about it.
If you're a 1911 lover, I'm not sure what the XDS would give you that a subcompact 1911 won't. The subcompact 1911s are right at the same size (a skosh bigger, not not by so much that it hurts concealment... if you can't hide a 3" 1911, you won't be hiding the XDS either), the same weight or slightly less (29 oz. for the XDs, 28 oz. for my Sig 1911 Ultra), and holds more ammo (6-7 rounds as opposed to 5). The XDS is likely to be less expensive, but probably won't be THAT much cheaper than S&W or Sig subcompacts (and will be more than the RIA subcompact).
Interesting gun, but by the numbers I think it's likely lacking. Not significantly smaller, no lighter, probably only slightly less expensive (unless they really surprise me with the price). IMO, it's good for folks who love the .45ACP but aren't into the 1911 platform.