Earlier today, Windows Central ran a story regarding a potential Pebble app coming to Windows Phone. Evidence for the claim comes via a Store listing for an internal app that demonstrates a Pebble watch syncing with Windows Phone 8.1 devices.
At the time, my position was that this app represents a proof-of-concept approach. If Pebble were pleased with the performance and feature-set, a contract to build the actual app and partnership would likely take place.
Speaking with various people familiar with the situation, I have been able to learn the full context of the Microsoft-Pebble state of affairs. The news is fascinating, but the outcome will cause some weeping and gnashing of teeth.