Tech site The Verge seems to have a pretty strong source at Microsoft. Having recently leaked the announcement that Microsoft are selling the Xbox 360 at $99 with a mobile-like 2 year contract (Xbox Live included), they have since turned to what are potentially two big announcements at Microsoft's E3 conference next month.
First is something called Kinect Play Fit. Microsoft are allegedly working on a heart monitor, codenamed Joust, that will track your fitness not just in one game but across all Kinect experiences. Fitness and tracking information will be sent to the cloud wirelessly, with the 360 keeping track of your fitness in most Kinect games so you can accurately strive to meet your weight loss and strength goals, whether you're doing push-ups in Your Shape or bowling a ball in Kinect Sports (Hey, we all have lazy days).
It's almost certain that if these two announcements are true that they'll be unveiled early next month at E3. Analyst Michael Pachter recently stated on The Bonus Round that we shouldn't expect many game announcements at E3 from Microsoft, but to expect lots of dashboard, multimedia and service announcements. With a new console almost guaranteed from Microsoft next year, first party studios will be busy creating next generation software so it makes sense that Microsoft will be tightening their Xbox Live service, which will carry over to a new console and integrates with Windows Phone and the upcoming Windows 8 OS.