Chris Clark's departure has led to a number of eulogies already, including this one by mainstay blogger(s) The Peerless Prognosticator. Community members at Japers' Rink are posting their thoughts in the original trade thread as well as this Fanshot.
But the best synopsis of the kind of player you're getting can be found at this link, summarizing an incident in 2006. Caps fans called him Captain Courageous or Captain Cadaver.
Finally, Rink Wraps for Clark's 2007-2008 and 2008-2009. Obviously, Clark's 2006-2007 was his best year statistically as a Capital (30 goals), but he's healthy again and has been a contributor this season.
I thought you folks might be interested to read the "mock arbitration" that unfolded last summer between the editors of Japers' Rink. Later, our guesses on Arbitration Day, and discussion of his reward.
Other worthwhile SBN-endorsed links to help acquaint yourself with your newest Slovak:
A comparison between Juice and Shaone Morrisonn (of the two defensemen the Caps were looking to off-load, you got the preferred player).
Juice's Rink Wrap for 2008-2009.
Juice's Rink Wrap for 2007-2008.