Lots of speculation around on the internet about what he might say, but here's my take:
First, I think DJT will do whatever he thinks will divert attention away from his other problems. Second, since he is going to make the announcement in Florida, he is going to say things that appeal to the hard-line Cuban exile community. And third, if Obama did it, he will insist it needs to be undone.
As far as concessions Cuba is expected to make, the only one that some might consider legitimate is the repayment for US businesses that were nationalized by the Revolucion. But as broke as Cuba is, that has pretty much a snowball's chance in heII. As the old saying goes, you can't get blood out of a stone.
Any other concessions come under the heading of trying to tell another country how to run their own internal affairs. Like our Prime Minister, I don't believe that one country should be doing that to another. Furthermore, what right does DJT have to try to tell Cubans how to run their country, when he clearly can't run his own.