“What could have caused this demotion in Pagerank? Any pagerank updates on anyones site?”

One possibility, which Matt Cutts pointed out, is that links in the SEO niche are passing less value that before.

I think it was just a coincidence that you PR dropped a point. Adding a no-followed link shouldn’t make any difference. There is, of course, speculation that linking OUT to prominent sites will help boost your pagerank, but it can’t matter for too long –because Google is practically telling everyone to stop linking without nofollow.

Another factor is that it takes quite a while for their algorithm to complete its processing and your recent change was most likely not taken into account for the latest updte.

Plus, it’s been a trend for more than a year that all of the sites seem to be “equalizing” in PageRank anyway. Realistically, this is how it should’ve been all along. An average, somewhat popular blog should only be a 1, 2, or maybe 3 in any index. When considered next to sites that deserve an index of 5,6,7 or 8, it shouldn’t be a typical blog. It should be cnn, amazon, or the likes. That’s my humble opinion, anyway.