Jack coming back to Salem is to be a temp thing, I think. No spoiler of any sort here, just me guessing my butt away. So anyway, I think Jack's back for a while to deal with Steve and check up on Abs. I'm hoping that Jack and Jen are still happy and together in jolly ol England. Jen couldn't come back with Jack because someone had to stay in England. It would make sense for Jack to come back because Steve is HIS bro.
As far as recasting Jen, I started watching Days while the'recast' had Jen. Stephanie Cameron. I actually LIKED her. To me, SHE is Jen. I know, i know, I'm in the minority here. But, When I started Days, She WAS Jennifer Rose Horton Deveraux. Not so much the Deveraux at that time, but still, she was JRH. So, I'd say a 'recast' here would be okay. I'd be okay with it.
I know that Missy originated the role of JRHD, but she's not the one I saw, and quite frankly, I didn't see what all the hoopala was about. In my opinion, Missy was no better than Stephanie Cameron, and Steph was no worse than Missy. One of the things that blew people away was that Steph and Missy could have passed of as twins. From what I had heard. To be honest, I'm thinking that is true. They did look alike. I hope that's not the reason Steph got the part. That would suck!!!! for her.