PC World has an excellent roundup of the various Froyo rollout problems, pointing out delays, problematic upgrades, and even cease-and-desist letters.
There have been myriad problems with the rollout. Start with the basics: Phone owners have no idea when they'll be upgraded, or even whether they'll be upgraded. Quite a few phones don't seem to be on the upgrade list at all, because they haven't even been upgraded to Android 2.1. Motorola's Web site detailing Android upgrades lists a number of phones, including the Backflip, Cliq, and Cliq XT that don't even yet have Android 2.1, much less 2.2. And the Devour won't even be upgraded to Android 2.1.
Motorola has also taken heat because Froyo on the Droid can't take advantage of Froyo's biggest new feature --- the ability to tether and create WiFi hot spots. The reasons for it are not at all clear, because the reasons that Motorola gave for it, such as hardware not being capable, don't appear to make a great deal of sense.
It's not just Motorola that has a problem. PC World notes that the HTC Incredible still hasn't received an upgrade to 2.2, and that Dell's Android tablet ships with Android version 1.6.
Some Android phone users have been so frustrated that they downloaded a leaked 2.2 ROM that a number of Web sites, such as MyDroidWorld, hosted. In response to the leak, Motorola lawyers sent a cease-and-desist letter to MyDroidWorld.
Why has the upgrade been such a problem? In large part, it's inherent in the arrangement that Google has with hardware makers. Many hardware makers, including Motorola and HTC, tweak the Android interface in various ways. That means that they have to tweak any Android upgrades before the new version of Android can be released to users. That puts hardware makers in a quandry: How much effort should they devote to the upgrades, which phones get the upgrades first, and so on.
Android has been a remarkable success for Google. But it needs to figure out ways to make upgrades go more smoothly.