Do most guys in their later 20's like to just "casually date" or are they looking for potential long term relationships? I used to think at that age people would want to start looking to settle down... but I am not thinking differently about all of that.

It's like asking if some prefer apples to oranges. It really depends entirely on what they want, what "period" of their life they're in, etc.

I know some kids at the age of 18 that want to get hitched, and I know guys in their early 40s that don't want to settle down just yet...

I have to agree with Sneezy.

Also, people nowadays are getting married allot later in life.

People are concentrating on their education, their careers, buying a house and being financially secure before looking for that special someone.