"The company also said that it will dial back efforts in multiple consumer markets and refocus its efforts on the enterprise market." -- I think this a smart move because they make business-oriented devices, not entertainment devices, but it might be too late.
ivyirwin's comment is pretty spot on. His points about having to click the video twice and there not being enough contrast were something that jumped out at me too.
I think the second block (the one with the three features, button and video) needs to be emphasized. Instead of being overshadowed by the top nav and the content below, it should be the opposite. Make the font size for the features bigger and change the icons to something more relevant (I would not necessarily associate those icons to those ideas by themselves). And, as mentioned before, the video should play once the play button is clicked.
Another thing that caught my attention is the difference in font sizes and how they don't necessarily make sense. Your headlines are smaller than the nav text which doesn't make sense in theory. I'm guessing you want people to check out the links in the nav but as mentioned before, contrast will do the trick. Also, you use two sans-serifs and I don't see the purpose in doing that.
The "What can Kuhcoon do for you" section needs a lot more whitespace and that headline needs to be bigger and clearer. Also, you should make both of those clients section entirely click-able, I think.
Finally, I get the image and the "Transforming everyone into social media butterflies!" text but somehow that whole block seems out of place: it might be an issue with the shadow above and the fact that a lot of the colors on the page are very similar.
I was going to say the same thing. I took a screenshot and looked at the space. The actual content uses about 80% of the width and 70% of the height of my screen. Ideally, they could've moved a lot of stuff to the sidebar to avoid the four bars you also mention.
I use Gmail for my personal and educational (Google Apps) and I haven't once gotten spam in my inbox (Google has caught all of them). I don't see why this better.
Good general advice. One remark though: while it is generally better to use designer typefaces, it's important to remember a lot of them weren't designed for the screen, but paper. As such, Garamond, for example (it's mentioned in the post), which is probably one of the best typefaces made, often doesn't work well on the web.