It uses a ton of common code. Virtually everything that comprises MeeGo already exists, and that which doesn't is mostly reference code for UIs, or is external to MeeGo itself (drivers, firmwares.)

In fact, most of the work now is packaging and integration I believe, with some device-specific work being done by hardware adaptation teams (N900, Aava.)

Now if you want to talk about reinventing the wheel, that's when you look at Android