The biggest issue is experience and comprehension
On one side, you have a generation going through the system, which has the world at it's fingertips in an instant. Where Google, Twitter, and Facebook are household terms, seeing more usage then oven, stove, or grill (also the fast food generation). Math is no longer done mentally or even long form on paper, but done via a calculator. Reports and essays now allow txtspk in them (and yet they can't read L337).
And on the other side you have this recent trend towards "no child left behind", which is going to result in little more than McD's getting more employees who have no glimmer of hope of getting any further than refilling the fry machine. The bell curve has shifted horribly towards the lower grades, further adding to the chasm between the top students and the majority. Though this opens up spots in higher education, we then see reports of schools and dropping enrollment stats as the majority now has no hope of even filling out the enrollment paperwork correctly, never mind passing the first term.
So we have a generation who is connected to the world constantly that either has no comprehension of how to use the information to the utmost, or they have long since surpassed those teaching them how to use it. Both groups would show a lack of interest in any classroom, though the current system caters to the former rather than strive to enrich the educations of the latter.