One thing I noticed talking to CS graduates from Harvard this year is -- entirely anecdotally -- more seem to be going to small start-ups. This has been an increasing trend the last few years, and strikes me as a big change. When I was a student, most CS grads went one of the safe and successful routes of going to Microsoft, Wall Street, or one of the name brand consulting firms. (Some losers went to grad school.) When I started as faculty, this basic framework still seemed pretty much in place -- the most notable change was that over the years Google took up a good chunk of Microsoft's previous mind-space.
Assuming it's true (and I think it is), there are many things that could be bringing about the change. Harvard in many ways is trying to promote it -- in CS our classes are much more "project-based", there's a student Hack Harvard group arranging sponsored Hack Nights, and there are institutional developments like the Harvard Innovation Lab to help promote an innovation culture. Part of it has to be attributed to the "Facebook Effect" -- we're bringing in more CS-interested people as students, and more of them are interested in startups, probably because some want to change the world, and because "a million dollars isn't cool."
One other thing that I think might be helping? Harvard's financial aid policies, which changed significantly around 2006, making Harvard much more affordable for lower and middle class attendees. I imagine it's a lot easier to take a risk right out of school when you're not deep in a debt hole. At the very least, it's easier to justify to your parents why you're not (immediately) taking that high-paying job after they've paid for four years of private college.
Overall I think this is all to the good. While startups aren't for everyone, I think Harvard grads as a group have historically been too "conservative" in choosing career paths; it's exciting to see what may be a change in worldview. A downside? We've been sending noticeably fewer of our best and brightest to grad school, as they're seeking other opportunities.
I'd be eager to hear from recent (and not-so-recent) grads their thoughts on the current startup culture...