Just as one aside on this, it's pretty clear by now that it isn't simply a matter of doing a source control get and the vendor's work is done.

Aside from simply having technical insight into the individual ROMs, you needn't look further than the disaster that has been Sony Erricson and Dell's Android entrants to see the truth in this -- those vendors came out with devices running dated Android versions, turning possible winners into catastrophic losers, eviscerating sales of the Streak and X10.

If they could have just done a merge and they were done, obviously they would have.

So now we're getting to the point where it seems that makers like Motorola and HTC have started to build up a significant Android talent pool, and that bodes well. Despite the constant incantations that Android is free, I wouldn't be surprised if the in-house development costs rivaled or exceeded what something like Windows Mobile cost to license.