Ubisoft has announced that certain aspects of Ghost Recon: Future Soldier will link to the free-to-play Ghost Recon Online.
In a bit of a throwaway comment after showing footage from both Ghost Recon titles, Ubi stated that it would be possible to carry achievements from one game over to the other. Beyond that, the link between titles wasn’t really expanded upon, but we’ll likely hear more details as E3 progresses.