Just a rumour I heard, I don't think it's anything more than a theory, but if it is true it's quite a big spoiler...
Spoiler:
I heard a theory that he might return as either a host, or it was actually a host version of Ford that was killed at the end of Season 1, and I'd imagine if it was true that they'd want to keep it a surprise so I wonder if they'd announce him as part of the Season 2 cast even if he is in it.
I've heard that too. Although,
Spoiler:
as much as I thought Hopkins was brilliant and Ford became one of my favourite characters on TV, I think the impact of his story would be lessened if it was a Host copy that Dolores killed. Him allowing himself to be the first big casualty of the rebellion he sparked is a fitting end for him. I'd love to see more of him in flashbacks etc but yeah, I hope it was the real him who died for the sake of preserving the impact of his character arc.
The camera focusing on the machine creating a new Host during Theresa's murder is still suspicious though. The big theory was that it was making a copy of Theresa to cover up her death but that was apparently debunked when Ford made no effort to keep her death a secret, only the cause. Since the finale, the main theory has been the Ford Host idea but I'm not completely giving up on the Theresa theory since we don't know if her death was ever public knowledge outside of Delos and the staff / board members are being killed off now. Actually, I've seen another theory that the whole Delos board are going to be replaced by Host copies in the outside world which is a really creepy thought