Time to Panic?
As a user and (potential) developer, Android's a really cool O/S and it gives users plenty of scope for installing applications on their phones (though just how many additional applications do you need to add before what you're running is a computer that's sometimes a phone rather than a phone with added functionality?).
To see this assumption that anything will run on any hardware platform lost will greatly reduce its utility but short of going down the Apple road of complete control over both software and hardware it's difficult to see how to avoid the fragmentation - Android's open so if a manufacturer is willing to spend the time and resources to customise it without any input from Google - something that phone companies are probably better able to do than PC manufacturers, then there's probably not much that anyone can do. It'll be up to the market to decide whether interoperability is a good thing or whether we'll be seduced by individual manufacturers' latest bit of flashy technology (though these have a habit of rapidly becoming mainstream must haves :-))