Welcome back!

Well, much of the patch changes that were made back in December mostly concerned the Duty Finder and post-game content, but there were some slight changes to the GUI (menu icons are now grouped together into six buttons, and the Character page has had some tweaks as well), plus also levelling has had a bit of a tweak - levequests and instanced dungeons are much more preferable to level with now as the exp they give has been increased. The main storyline and sidequests are still worth doing however. Really, most of the changes only affected end game so don't worry about that too much at this point in time.

Really though, a bit of advice I have is don't fall into the trap a lot of players did by rushing to level 50/end game and then finding they've burned themselves out. Take your time, savour the storyline and your surroundings, and enjoy the journey.