Here's a strongly written opinion piece from ComputerWorld's Android Power blog called "It's Time for the baked-in Android UI to die." JR Raphael doesn't hold back when he thinks something needs a fork stuck in it, and he says Sense, MotoBlur, TouchWiz: You guys are so DONE.
Manufacturers make their own added tweaks to Google's native Android because, face it, most of the hardware out there is for the most part the same stuff. The User Interface (UI) adds some style to what could otherwise be a "me-too" device. That's what HTC's Sense, Motorola's MotoBlur and Samsung's TouchWiz are: UIs that sit atop the Android OS, customizating your interaction with your phone.
The UI also ensures that as long as you're waiting for an OS upgrade, you'll wait even longer for your phone manufacturer to put their own particular UI branding experience (or Android skin) around it. And in these days of cell phones and teh Internets and Twitter and Facebook, nobody wants to wait a few extra nanoseconds for something they could otherwise have right now.
Raphael says look what's happening with Froyo (Android 2.2): Some phones are shipping with it, some are just starting to get their over-the-air updates, and most don't have it at all. But even worse: new devices shipping with really old Android. Look at the the Dell Streak and the Sony Ericsson Xperia X10: both released clothed in manufacturer-specific Android 1.6! Have a Donut.
Original Android was pretty bare-bones, but the newer releases to the OS have been getting more features and curb appeal. Third-party apps, widgets, and add-ons allow even more for the power user or the would-be screen designer. Manufacturers, however, want to put their own spin on the handsets they release.
So Raphael suggests they continue doing so, but stop "baking in" their modifications into the actual operating system. Make them standalone apps, but allow the cutomer to revert to stock Android. It will allow easier and faster upgrades to the OS, and turn your liabilities of incompatible OS tweaks into software assets. Raphael didn't say it but I will: some of these modifications from stock Android are basically bloatware. It's time to let the customers be right again by letting them uninstall what they don't like, use or need.