It's no secret that the Motorola Droid's ace-in-the-hole is the Android 2.0 "Eclair" operating system that's on board. The big question on everyone's mind is, will existing Android devices be able to upgrade? The answer is yes. Sort of.Android 2.0 is the coming-of-age update that Android lovers have been waiting for. It brings such a wealth of new features and capabilities, it puts the Android platform near the top of the heap when it comes to smartphone operating systems. Motorola should consider itself lucky that it scored the lead on every other Android handset maker out there, as it will be first to market with Android 2.0.

But there are already a huge number of people out there who were the early adopters of Android 1.0. What about them? Well, many have already updated to Android 1.1 or hopefully Android 1.5. Android 1.6 should be rolling out to many of the existing devices soon. But Android 2.0 is where its at.

Thankfully, at least one handset maker has confirmed that it is working to bring Android 2.0 to at least one of its devices. HTC said, "Yes, we are working on an Eclair update for the HTC Hero. Because Eclair is a significantly enhanced release, it will require some time to update Sense for this new version of the Android OS. Please be patient while we work to provide you with a tightly integrated experience like the one you are already enjoying on your Hero."

The Hero, of course, is the Android device that HTC announced back in May and is now for sale from Sprint here in the U.S. The Hero uses HTC's Sense UI, which is a really slick overlay that rests on top of the Android platform. On the top level, users interact with Sense, not Android. This is the same concept as HTC's own TouchFlo 3D, which rests on top of top of Windows Mobile.

HTC didn't said if or when it or its network operator partners will be offering Android 2.0 updates to its existing lineup, which includes the G1, the myTouch 3G and the Tattoo.

Keep in mind, one of Google's core tenets for Android is that it be updatable over the air. I'd be pretty surprised if handset makers ignored this -- and even more so if Google didn't call them out on it.