It seems to me that Spiral Knights is not hardly "dead" by my standards. Look here for the amount of people playing SK: http://steamcharts.com/app/99900
It seems Spiral Knights has had a sudden increase in players. Please, Grey Havens, take note of this and post some messages or something talking about new content on the way.
:(
Or just give us new content...
I dont think any free to play games ever truly die, there are some people out there who dont want to spend money on games. Also even though theres 800 players average this game is way past its prime.