Hmmm... so blogger.com now supports labels for posts. Since its a Google product, I am guessing that labels will influence search engine relevancy, especially if the label appears in the title or post text. Same would apply to tags at other sites.
Meta-tags haven't been relevant in SEO for a couple of years now, but perhaps Google is thinking about (or has done it) giving weight to content tags? This is pure speculation, I haven't the foggiest idea. Although I have noticed that I have gotten a lot of traffic to my personal blog when search engine queries match my labels. Interesting.
This is an amazingly innovative, yet simple (since options are already traded) concept that Google has innovated - creating a market for their employee stock options. One simple concept that just raised the value of their compensation packages measurably. Well done, Google.