...The hardcore aspect was more like XI's view on hardcore. IMHO, XI's endgame was viewed much more difficult (see: timesink) than that of WoW's, however XI didn't have the appeal that WoW did for the general public. I wouldn't mind making the first 80% of the game casual friendly, but that last 20% should be painstakingly tough, and really provide a challenge to the hardcore players/XI enthusiasts (which there seems to be a decent amount of).
I do think making the game a lot of the game casual friendly (questing exp, content solo-able) is a fantastic idea to get new players who normally wouldn't play to join, however in that same aspect the game's content shouldn't be sped up to accommodate. Leveling shouldn't take a long as it did in XI (considering how vastly different they play) but it shouldn't be as hasty as it is now. If content can be done at a casual pace, than the progress should reflect that.
I fear that in an attempt to get people to enjoy the game in the short-run (have a good launch, high number of subs), the game will be designed exactly for that; no long-run enjoyment. There will be a focus on having fun now, instead of spreading it out (which XI did a great job of, albeit it took a certain type of player with dedication to actually appreciate the system).
TL;DR Make content casual accessible, but not easy/short. Make endgame content exceedingly difficult to keep players in long-run; like WoW but harder.