Google has updated the two-week survey of Android devices connecting to the Android Market again, ending yesterday, May 3, 2010.

According to their graph, 99% of users are using platform versions 1.5, 1.6 or 2.1 with the final percentage being split among some very minor releases. More than one third of Android devices are still using a build of the Android OS which is several versions old - 1.5.

With the HTC Hero and Samsung Moment 2.1 updates rumored (for the 7th time) to go out this week, this will hopefully be the last time we see 1.5 ahead of the pack.

Google has promised to fix this fragmentation by detaching the Android OS from functionality and features specific to carriers and manufacturers, so that the custom UI makers (Sense, Rachael, etc) don't have to test and merge as many components as before when releasing when upgrades to customers. Google’s de-fragmentation work has begun in the Android 2.2 release (codenamed Froyo) rumored rumored to be made available this month and will continue with the Gingerbread release (no version number is reported yet, maybe 3.0?).

With the current state of affairs - multiple devices from multiple manufacturers on multiple carriers on so many different versions - users will still be at the mercy of the manufacturers and carriers to release an Android v2.2 or later update to their devices before the de-fragmentation will truly begin to take effect. It will be interesting to watch how Google will notify users of carrier-agnostic Android updates without a common synchronization software package similar to iTunes; Apple’s engineering allows users to see that an update is available as soon as they plug their device into their computer.

It is also worth mentioning that older devices, such as T-Mobile’s G1, may not have the capacity for an OTA update of an entire Android build. Older or less-featured Android devices may not contain sufficient internal memory to download a full OS image, and may need software on their PC, at best, to install while their device is plugged into wired connection or, at worst, require a trip to a retail store for an upgrade while they wait. Forcing users to make a trip to a retail store in order to get an upgrade will result in residual fragmentation despite Google’s efforts due to user laziness or misunderstanding of the benefits of upgrading their device, though it may give retail stores an increase in sales of newer devices.

The other question worth asking: Will Google begin to drop support in the Android Market for devices which do not (or can not) upgrade? Given the growth of Android application development in 2010 so far, it will be interesting to watch the ratio of apps which will only work on 2.x releases of Android. More than likely, however, it will be application developers, and not Google, that drop support for older Android releases.