If you only played at launch then yes it's massively improved, even ground combat is actually fun now
If you last played in the past 6 months theres little point checking it out just now unless you want to see the new ground combat. The sale of Cryptic and the transition to being owned by Perfect World has put a nasty dampener on the content releasing, the hope is now that everything is finally confirmed they can get hiring more devs and get content cranked out faster.
Oh and this weekend has a double XP event thingy on (seems its double everything, XP, credits, badges etc. Just not doubled from PvP)