The master blog (http://blog.stackoverflow.com) has a new shiny design, and is quite content rich now, and believe it deserves a prominently placed link.
The blog is the area where Stack Overflow as a company report news, business matters, and changes to the sites and how they are working on new things (etc). As such it matters to all users and so is an important aspect to the experience on all sites as a whole.
It would be good if more users read it, as they'd pick up more info and knowledge about the company and the site's workings - which can only be a good thing.
The blog is worthy of more dignity than this!
As such, I believe the most suitable and natural place is a link on the black top bar. (Actually on the top bar, not in a drop down.)
Not sure of the exact place on the top bar, as I'm sure there'll be considerations I'm not aware of (responsive design requirements, future plans for top bar spaces etc).