I looked at that password list. Only around 1800 passwords were kept in regular md5, those are piss easy to crack (see http://www.md5decrypter.co.uk/ if you don't have a rainbow table setup already). The other 60000 were using some other format I did not recognize, though possibly by my own fault... they remind me of Wordpress passwords. It's probably some combined multiple md5 + hash, so I'd think that they are difficult if not impossible to crack, especially if you used a password that is long enough with a wide enough character set.

The danger for password reuse is very real though. It is in theory possible to find a less secure password from some site you signed up to, recover the password from there, and use it at mtgox with your username. So if you use the same password at mtgox or anywhere else, you'll NEED to change passwords. Otherwise you are fairly safe, provided your account is not one of those with regular md5 hashes (the ones not starting with $1$whatever are regular md5s).