In addition, older Android phones may begin to exhibit hardware limitations preventing them from accommodating updates, making it more likely there will always be multiple versions of the software in the market.

At the time of the Droid release, Motorola, T-Mobile, Google and Samsung all declined to comment about whether existing Android phones would be upgraded to version 2.0. Some phone makers may be slow to support updated software because they have developed custom user interfaces -- like Motorola’s Blur and HTC’s Sense -- that must be updated at the same time.