Gamereactor asked Bill Roper (formerly with Blizzard North and Flagship Studios), who recently joined Cryptic Studios, some questions about their upcoming game Champions Online. He mentions some of the lessons he learnt with Hellgate: London.
"Something comes up each week where I draw upon both what has and has not worked in my past games. Perhaps the biggest lesson learned is maintaining a focus on what's vital to the game. With Hellgate: London we simply tried to do too much and spread ourselves (and our ability to properly test and balance the game) too thin. Also making sure to have a solid base of social and community features is vital - as is constantly staying in contact with our players."