> Absolutely, one should never use the same password for two different sites.
Why not? I have the same password for facebook and google.plus. I have the same password for LWN and /. (but different than FB and G+, and now the LWN admins know my /. account ;-)
And I use the same password for all those stupid 'register here' crap (NY Times, etc). Thus if you break into one of my accounts for posting on a news site, you can pretty much post as me on all news sites.
But do I really care? No.
My bank password is unique, my VPN password is unique, basically I have a separate password for every thing that actually matters. If I had a linkedin account (which I don't and delete once a week a new 'invite'), it probably would have been the same as my FB account, or my news account. Thus this break-in would only allow the attacker to mess with my virtual identities but not any of my real ones.