They should be developing this in Unity. You can publish to Win, Mac, all major browsers, and iPhone/iPad. Not only that, you get actual 3d rendering support, including PhysX, and a nice content pipeline.
How would Unity integrate with Facebook, and send SMS messages?
the same way any other app would
Unity publishes web apps. I assume you could embed them in any web content, including FB, however, you'd need your users to install a Unity browser plugin.