So I know that a good part of the feelings of the community is dread as far as the changes in lotro. They're changing the skill trees (thereby causing everyone to relearn their class), no more raids, and just overall huge changes to what we used to know. I've usually been doubtful of what new expansions bring, as often kinships turnover a good part of their population from expansion to expansion. I've been playing lotro since it went f2p back at 65, and it seems that anticipation isn't as high for HD since RoR/Wildermore did not meet expectations (only 1 raid cluster, no instance released with wildermore, gold gear endless grinding (especially kills me with multiple alts), no locks allowing for mindless eternal grinding (and reducing interest in scheduled kin raids), early FA release signalling the end of that level cap). I figure that the major reason for that was because there were major overhauls taking up most of the resources (mounted combat for RoR, preparation for HD when wildermore was being finished).
Anyway, here's my thoughts on some of the good aspects of the expansion: (some views may have been said already, but didnt want them to get lost in the threads of others)
1) Skill Trees - changing from selected traits to trees will help in the long run (and yes will be crazy). Since lvl 65 (when I joined), there's always been new skills with each expansion, and only modifications of the already limited class trait slots. So while more and more skills were added, modifications to them were limited based on skills (unless expanded in updated traits)
2) Raid/Instance expectations - it appears that with only one 12-man Big Battle release, and the announcement that FA's will be unavailable with release, that is GREAT news in the sense that we can then expect a future instance/big-battle release in the future. I love multiple raids per expansion pack and while there was only one raid cluster with RoR, I hope the future cluster will have 5+ 12-man wings/instances.
This stuff probably has been said before by other people, but I just wanted to give my 2 cents as to why HD could be a great expansion for the future.