There has yet to be any official word from Bungie, but an update to their Careers page has listed an opening for a PC Compatibility Tester. The first question is, does this mean Destiny is coming to PC? Maybe, maybe not.
The job opening certainly makes it look like the developers are encroaching on a PC release:
Testers at Bungie are grouped into teams, responsible for ensuring that an area of the game is ready to ship. The PC Compatibility Tester will evaluate PC hardware-specific features and ensure various systems work together across multiple PC configurations to provide a great experience. This is a challenging area to test, so we are only looking for the most resilient and technically minded testers. If you love solving new problems on a continuous basis with an eye for detail, you will love PC Compatibility Test at Bungie.
Prior to Destiny's release in September of last year, Bungie admitted that it was a possibility, but they needed to focus on the console release first. With a year since the game's release closing in and the upcoming The Taken King expansion, it wouldn't be a stretch for Bungie to be looking towards a new platform.
We already know that Bungie is working on post-The Taken King content, but who says that can't be PC-related?