The much awaited “Cupcake” update for Android is finally here. Just a few days after developers first received version 1.5 of the mobile operating system, along with the corresponding SDK, T-Mobile USA and UK have reportedly begun pushing an over-the-air update for all G1 users. Some of them already received the 44MB download overnight, but the roll out is expected to last throughout May.

Android 1.5 brings a number of enhancements, including on-screen keyboards, more home screen widgets, video recording, stereo Bluetooth, and faster browsing courtesy of both new JavaScript and WebKit engines. The onboard GPS has also been upgraded with quicker satellite acquisition times and several user interface enhancements have been made to the email client, calendar and contacts. All in all, the update is a long-overdue and welcome one; if you happen to be a T-Mobile G1 user let us know how everything goes in the comments.