Dining room reservations
Marc I sent in an inquiry earlier today on the dining room reservations will let you know when I hear back.

Upgrades
I also believe that they will continue to offer paid upgrades. I would be surprised if there are many "space available" cabins to upgrade to but it sure sounds good from a marketing perspective.
I will probably get no more clarity on that question - it says "Eligible for suite upgrades at time of sailing, when available with preference by booking date" I think that is all we will get. I can imagine the poor reception desk on embarkation with all guests E and above wanting to know if they were upgraded!! This wont work too well in my opinion.