My son will be 18 yo next month and will not be a college student. Will I be able to claim him as a dependent for 2012 taxes next year?

If he goes to high school through May 2012, yes.

Even if he is NOT in high school or college, you can claim him if he make LESS than $3,750 in 2012 AND you provide more than half of his total support. He does NOT have to live with you for you to claim him under these provision.