In my opinion, get CS, and spend your free time on Bio or take some courses from that departmant. Otherwise, your CV may not achieve to the desk of Human Resources (in some companies). Your previous experiences, knowledge and projects may not be seen. Especially web based job applications give you a combobox with only fields of CS, EE, Math, Physics, Statistics etc. and you can't even apply. Of course you may not want to apply that kind of company that constraints your creativity to design a CV.
After high school, I've started Economics. And yes, I was learning nice stuff about how the world rules. But as you said, ">50% classes was worthless". After a while, I met the programming. In my country, the big slice of software development pie was accounting and database programming (ERP, CRM, ..). Then, I quit my education, and started new one. Now, I can learn in 6 months in school, what I could learn in 2 years by mysef. It realy speeds up the process. I'm participating in student projects with electronics students. Lecturers give me nice suggestions...
But success doesn't depend on diploma. In one way or another, you can do astonishing works.
+1 to CS =)