CampBulletin: You will experience this if you are using one of the Google Fonts that does not have a bold weight associated. For example, the font Actor has only weight 400 (normal), but the Mesocolumn options-css.php file and the superfish menu css assigns the weight of 600 (semi-bold) to headers and font-style: bold to menus. Furthermore, most browsers by default assign all headers a weight of 700 (bold), so the blurriness is due to your browser 'fake bolding' typefaces which do not have a proper bold style defined. That's probably why the Kindle looks OK (as it doesn't have the built-in bolding, I'd guess).
If you definitely want crisp fonts, and definitely want to use a Google Font, you have 2 choices:
OPTION A) Choose a Google Font that has a 600 & 700 weight option. You can see which ones do by heading over to http://www.google.com/fonts and look for ones which say they have 14 styles (you can click to see all the variants).
OPTION B) If you are confident with code, you could alter your css to override the theme's enforced semi-bold / bold settings.
@Richie KS: I would strongly recommend any future releases of the theme do not make use of !important bolding hard-baked into your heading/menu styles to allow maximum flexibility. I've been trying to un-force this and it's been a lot of investigative trial & error.
There's a great post on this very topic here: http://css-tricks.com/watch-your-font-weight/