Just spent some time with friends who are just casual internet users. Both spontaneously said that they hate mobile sites. I see no reason to develop one.
Add me to that list, I hate mobile websites and never stumbled across one that is in any way better than the full version. Even on my smartphone I have enough power and can zoom in, if need to. A 9"-10" tablet should make no difference to the user of the full site. It gets worse when you are familiar with the full site already and try to find something in the mobile version - awful experience. Being able to effectively set Desktop UA is the only reason I use Dolphin on my mobile devices.
My personal opinion, and again this is my opinion, if your full website needs a mobile version to be useful - your full site has failed in UI.
If you want to be mobile friendly - have an app. It gives you much more to work with, better experience, more flexibility and much more interactive than a dumbed-down version of a website.