Yes, the top of that screenshot looks messy. If they are moving in this direction, they could also get rid of the top panel. Or at least redesign it.
I have been working in a similar desktop on my wide-screen laptop for nearly a year now. I feel much more productive. It took me some time and skills to configure it, but the tools are already available. I use Openbox+Tint2+Conky and some other lightweight utilities. Also Tree Style Tab extension for Firefox: https://addons.mozilla.org/en-US/firefox/addon/5890 Since they are talking about getting users to the browser faster, they may as well tweak the browser to work better in this environment.
It is more natural when window/tab hierarchy flows from left to right, than from left and then from top.