Having a college degree is an important social signal in the eyes of most people. If you're only going to be in college for an another year, I'd say go finish the degree. Plus, the college experience isn't something you can recreate later in life. Take advantage of it while you can.
You'll also have the opportunity to try new classes and fields within CS. It's hard to get a wide view of CS otherwise. A solid foundation will open up more options in your career.
My college life is different though. I was in the Marine Infantry for 4 years. So I came out older than everyone already. The only college "thing" I do is go to the library.
Would switching to part time at finishing your degree while you freelance as well be an option? That might you allow you to try out lots of different types of CS/programming/development work in different industries and build some history and contacts while school is finishing up.
Stay in school, coast if you want to, work on personal project and have fun and socialize. You will probably never have as much free time again. I got out after 3 years and looking back I think it was a mistake.
College is also a really good place to meet and work with people who could eventually become your technical cofounders, the scarcest ingredient for most startups.
From an economic perspective, would it cost you less to
1) Stay in school (pay tuition) and continue doing part time work during the school year, and do a summer internship this summer, or
2) Leave school and work full time, but pay for living expenses?
I am a CS Junior as well, but I wasn't in the Marine Infantry. I agree with pradn about the social signal of having a degree, but how do the costs play out? And do you already have any full time offers?