I'm a second year CS student.
I don't think that you have much to fear from the huge number of drop outs. From my expercience those that drop out:
a) Feel they are "finished school now" and so don't need to work in any way shape or form. Go to lectures!? Nah! I'll just photocopy the notes from Bob. Bob...c'mere...oh you weren't at the lecture either? Oh well. He can't have said anything too important now can he?
b) Have no interest in computers/technology/maths/science/knowledge/etc. They are of the opinion..."I can check my e-mail, how much harder can CS be?" Plus I have a friend of a friend who made shitloads of cash a few years back from doing websites. And he didn't even have a degree!
So assuming you are not like that, then I don't think that you should be too worried.
Oh yeah, and another thing...you'll probably have a small group of arrogant, condescending, pretentious nerds, that did nothing during high school but program. They'll do their very best to make you feel inferior.
Ignore them, you'll have the last laugh when it comes to results time. They often don't do as wonderful as they expect they will.
