A lot of the points that they brought up in the liveletter were great. Hopefully the content can live up to it.
Island Sancturary sounds awesome and is the one I am looking forward the most. Just being able to have your own huge island where you can gather and build things sounds nice and relaxing. Hopefully its like they described it.

Being able to do the variant dungeons as a solo players is great. Hopefully its interesting enough to do it for more than one run. The same with the criterion dungeon even if you need three other people. Probably wont do the savage one though but still nice that others have the chance for harder content with smaller groups.

Hopefully the relic will be doable with a variety of old content. I greatly disliked the Eureka one and was not a huge fan of Bozja either.