I have found some really pleasing uses of Merriweather over the last few years. I would love to show you a few I particularly like.
I also wonder where you use Merriweather or what uses you think are good ones. Please post some URLs!
Google ventures - http://www.googleventures.com/
WordPress - http://wordpress.com/
Methodologie - http://www.methodologie.com/
Kerem - http://kerem.co/
Camp Sharrow - http://www.campsharrow.com/