All of the above stipulated, we can not ignore the sales figures of the past quarter: nearly half a billion smart phones. Sales for the current quarter are predicted to be much higher, still. Share of user base is on a rapid rise, 400% from 2009 to 2010, and expected to be an equally astonishing rise through 2011.
Mobile is more than the next big wave. It is changing the landscape forever, and will demand the best that developers have to offer. If your user base is in close parallel to the general numbers, then you know your site(s) is(are) in for a change. Bag it if you will, for now, but don't believe you won't have to pull it out very soon into the near future. Better, now, to learn and study and prepare to be on crest of the wave, not swamped by it.