What I have been seeing in the last year, and much more accutely in the last few months, is that the demand for top end developers has outpaced supply dramatically. I am seeing rates for senior/lead programmers up to, and I swear I am not making this up, a good 40% higher than just 18 months ago. I have seen many recruiters and HR deparments showing up on the freelance sites, trying to get senior talent. Its crazy out there right now!
Demand for mid and entry level talent seems to be about the same, best I can tell.