Perhaps the most exciting part of the new Merriweather release ( 12/26/2013) for me is a font developer geek discovery. I seem to have found a way of passing manual hinting into the auto-hinter TTFA. TTFA is what hints 99% of the font. It does a great job. But for the lower case g and the capital letter Ef if Cyrillic I was not happy. By passing manual hinting through TTFA I was able to get rendering of both letters to improve in Windows XP and Windows 7. This means even higher quality is possible for people using TTFA. I will be working to find out precisely how & why this happens with the author of TTFA Werner Lemberg so more people can take advantage of it. In the meantime if you want to try this – manually hint a glyph – say the ‘g’ for instance and then check the ‘pre-hinting’ checkbox in the GUI of TTFA. I’ll be interested to hear what people discover.
Merriweather on Flickr
Merriweather Font 
Off topic comment, but since I saw hyphens in your post (or is than en dash?) let me bring it; I have been trying to use Merriweather Serif in a web site a while ago, it is a great typeface and I really like it, except the hyphen: it is very high for lower case letters and looks out of place, like if I’m using the wrong character not a hyphen (and it was specially anooying since the site was using automatic hyphenation). Is there a reason for the high position of the hyphen? Can it be improved, even if by providing an alternate glyph?
I will be fixing that. The explanation is that when I made both the serif & Sans originally I tried to find a height for the hyphen & other dashes that was a compromise between the lower case and the the caps. The compromise was clearly too high! The new serif has a lower position for the hyphen and other dashed because I concluded that I would make a CASE feature for the version you can conventionally license that would address an all caps instance and so I could let the hyphen be genuinely lower case oriented. I expect to update the Sans to follow this. The Sans does not have the new hinting yet and needs that. I would also like to add a few more glyphs to add support for a few more languages. Indeed I would love to expand the Sans to support Cyrillic but we’ll have to see what Google wants in that case. That’s too much work to just volunteer to do it!
That is great! Let me know if there is anything (font development-wise) that I can help with.