Indiana University Revoke

I got accepted to Indiana University in September (2011) with a 3.1 gpa and for the first semester of my senior year i will end up with about a 2.75 gpa with grades:

AP enviro: 79%
Adv composition: 86%
Government: 86%
Entrepreneurship: 84%
Calculus: 66%
Physics: 75%

How likely is it that i will be revoked or put on academic probation?