I had a professor at ERAU who flew with Northwest for a pretty long time with around 22,000 hours insist almost every week that GPA does not matter. I agree with him in that intelligence and test-taking skills don't always correlate with flying skills and prompt and accurate decision making... BUT, ERAU has a network where jobs/internships/co-ops are all listed, and each of those positions list their requirements. A lot of the good ones such as Internships with FedEx and many major airlines say you need a 3.0 to be able to apply. Luckily, it seems that most of these are for internships, but some are for job listings too, and it might also reflect on something they might at least look at when you apply. The minimum GPA I've seen listed was 2.5 to be considered for certain positions, but some companies don't list one at all.
In sum, GPA doesn't make you a good or bad pilot, it just comes down to which employers think you should also have good grades to go along with it.