Check out the Intruders.TV interview with Kevin Rose.
One of the cool things about being an entrepreneur or in VC is that you do not need to dress up to go to work -God knows I wish I didn't have to wear a tie and dress shoes everyday. Kevin Rose has made a lot of money for his investors (and for himself) so nobody is going to fault him for wearing a hoodie.
The guy interviewing him, on the other hand, looks like he fell out of a Fall Out Boy video.
A finance guy would never come to the office - would never leave the house looking like that. "Casual" for a finance guy is pressed shirt, no tie; or khakis and a polo shirt if you are getting on the yacht. Part of it is a function of age (important finance guys are often a decade or two older than important VC/entrepreneur guys), but part of it is also a measure of culture:
compare this guy:
or any of TheDeal.com interviews http://youtube.com/watch?v=qZhZF0KhuX4.