Maybe this one instance isn't that big of a deal. I however ask "What's next ?". If google gets away with making "tweaking" of the Android system harder to do, what will they do next? Will they try to stop it all together like Apple ? Will limit apps like Apple ?
There is a bigger picture here. Some of us just have trouble seeing it.
This is an argument used very often in the world of iPhone jailbreaking. The difference here is who we're dealing with. Yes, Google is a megacompany interested in making money. However, Google plays the game differently than Apple.
1) Android (as an OS, the basic, functional piece of software Cyanogen and others modify) is open source. Apple's Touch OS is neither open source nor open. The whole idea of Android is that it is open in the first place, but one must recognize what he is referring to when discussing "Android".
2) Google is only protecting their rights as owners of the closed source software they distribute. Whether or not an application is "free as in beer," you cannot assume it is safe to redistribute it on your own. YES, you may have paid for it. YES, it may be free, but that doesn't mean it's yours to pass around. I think the line was blurred here, because people assumed Google would never jump on something so trivial, but now that they have, it doesn't mean they're the evil empire. In fact...
3) Google wants Cyanogen and the like to continue making ROMs. They want Android devs to get creative. We've seen what companies like HTC and Motorola can do with Android. What if someone took it that far and made a less-bloated, more feature-filled, fantasticly sexy version of Android that far outdid Sense or MOTOBLUR? Maybe it could even be monetized so that they could pay for the licenses to redistribute the very pieces of code Google wants credit for.
All in all, I don't think it's fair to compare Google to Apple. I also don't think that we're at the end of all things awesome when it comes to Android modifications. Just sit back a bit. Watch what happens. Cyanogen and the crew at xda-dev are already working on an answer to the problems the C&D presented. While it may feel like a slippery slope toward hell, it's not. We've just got to rethink what rooting and modding means.
And if you think this is bad, spend sometime in the jailbreak scene. Every firmware or hardware revision, Apple throws another curveball and the devs have to start all over again.