The update, which has also been known as Cupcake, was originally supposed to be pushed out to T-Mobile G1 users last week, but the fourth-largest carrier delayed that by a few weeks because of deployment issues.
"We are working diligently to get Android 1.5 out as soon as possible, while aiming to ensure a consistent, positive experience for our customers," T-Mobile wrote in its community forums. "We're finalizing the build this week to ensure optimal functionality and smooth delivery."
Android users eagerly await the update because it adds a host of new features to the Google-backed mobile operating system. One of the most appealing new features of Android 1.5 is the addition of a virtual QWERTY keyboard. This will likely be a convenience for handsets like the G1 that already have a physical keyboard, but it's a necessity for upcoming Android devices that are touch-only, like the HTC Magic and the Samsung I7500.
The update will give Android the ability to record videos, and these can be easily shared with a native YouTube uploader. The 1.5 version also will strengthen Android's ties with Google's Internet services and make it easier to upload and share photos via the search company's Picasa photo-sharing site. The Cupcake upgrade adds stereo Bluetooth capabilities, home screen widgets, improved browsing speeds, and faster GPS location gathering.
InformationWeek published a 360-degree analysis of the first Android-based smartphone. Download the report here (registration required).