The interesting bit is that on the conference call they did say that that was actually not the plan (most likely to keep the other android partners comfortable). Supposedly their process for Android remains the same and Motorola will be on the same footing as everyone else when it comes to software access.
This says that the deal was 100% about patents and nothing else, which in turn says it wasn't that great of a deal in the first place (considering as they paid a big premium for the patent portfolio).
But assuming that they break their promise to partners and do what apple does too by designing both hardware and software together: it would be a good thing for Google as a phone maker, but a nail on the "Android as open" coffin. I don't think they'll be able to risk a move like this - angering their partners and probably breaking Android up -, which just means that the actual impact this will have on the quality of phones coming from Google and Android as a mobile OS is slim to none.
I sure don't hope that Google bought Motorola for that. It will fail just as all other mergers that look good on paper do that.
You got two big cultures coming from completely different parts of the tech world. There is no way that you will get seamless vertical integration that way.
For example, note that Gruber does NOT point out how the acquisition will allow Google to do Apple-style seamless hardware/software design.
edit: Android -> Google as pointed out by m_eiman below