One app sorely missing with Windows Phone is Photosynth. You already have a desktop application and, to the dismay of some, an iOS app for Photosynth. We've heard that Windows Phone was a top priority with Photosynth and it now looks as if a Windows Phone version is close to being released.
The website GEMIND has stumbled upon signs that Microsoft has been creating accounts on the Photosynth website to test the integration of a Windows Phone app. They have even stumbled on test photo sets on the Photosynth website that appear to be have taken with various Windows Phones.
For those not familiar, Photosynth stitches together series of photographs to create panoramic images. Microsoft stalled on developing a Windows Phone version of the app due to camera API issues. Issues that should have been resolved with the Mango update.
No clue as to how close the development is but based on the dates of the test sets, a Photosynth Windows Phone app might be just around the corner.
We'll echo GEMIND's sentiments on the issue, It's about time Microsoft.
source: GEMIND; Thanks, Rodrigo, for the tip!