Ken and Mayim have been announced as official co-hosts, so they'll be switching off. I also believe Buzzy Cohen will have some involvement (he might be hosting the Tournament of Champions). They've also disbanded the Clue Crew, with Sarah taking a production role and Jimmy assuming the stage manager duties full time.
Last Tuesday's show had a REALLY stupid wager. The woman in the middle answered a Daily Double clue correctly and stormed back to take the lead going into Final Jeopardy (she had $16,600, while the champ had $15,700 and the other challenger had $11,000). Quite coincidentally, the category was British Royal Family, and the clue was: "Prince Philip’s titles included Baron Greenwich & Duke of Edinburgh, but not Prince Consort, last used by this royal." Correct response: Prince Albert.
The other challenger got FJ wrong. Then the champion got it right and bet everything but a dollar. When they went to reveal the woman in the middle's response, you could see in her face that she had screwed up. Her response was correct, so you knew she had botched her wager. Instead of betting enough to cover the champ doubling his money, she bet $1,801, so she fell far short of winning.
It took a while, but here's the convoluted reasoning for her wager: She was apparently counting on the champ wagering $901, which would have won the game for him IF he got the response correct and she did not and bet $0. Her $1,801 wager would cover her in the event the champ wagered $901 and got it wrong AND she also got it wrong (in that case, they'd both have finished with $14,799 and gone to a tiebreaker). This is beyond baffling because of the number of "ifs" that would have had to happen. How you don't assume that your competitor, who is less than $1k behind you, won't double his money and wager to protect against that is beyond my comprehension. I guess she wasn't totally comfortable with the category, but she obviously knew enough about it to get the correct response, so maybe it was an unwarranted lack of confidence, but you gotta bet on yourself.