I returned 2 months after DF release and I'm enjoying it with the little time I have.
They've added a BoA token catch-up mechanic with fairly decently drop rates so gearing up isn't that difficult. If you plan on returning you should focus on getting 1 character up to renown 20 for all factions and getting Worthy Ally before creating more toons. Dragonriding is a neat mechanic that makes travel pretty fast in the Dragon Isles.
I'm a casual player so raiding isn't my thing but there's tons of content to keep you busy overall. If you enjoy raiding you'll have to get info from someone else. I just enjoy collecting things and getting achievements.