I can echo this. I've had two Fortune 500 companies, several recruiters, and even Google all contact me (unsolicited too) within the past month. It's the oddest thing I've seen in the 13 years I've been a developer.
Because if it's the latter, startups can continue to siphon off from universities (through internships, and later job offers) and the like.
I'm a freelancer, and have been suddenly deluged with new projects in the past fortnight. I'd chalked it up to coincidence, but I keep talking to other people who are experiencing the same.