Try out a new class. If you're gonna try sage/reaper, be sure to buy a level 70 ilvl 400 gear set for them in Rhalgar's Reach
Were you interested in clearing PotD/HoH?
Any glamours you want to work for?
Any achievements you really want?
Anything you'd like to prepare for 6.0? Your current gear level, Item space, potions, food, FC rank 3 actions/squadron manual for 15% EXP bonus, ect
Any side content that you haven't done yet?
But focus on what you know you'll be doing in the long run first, and when you have that checked off, then move to the next thing~