I don't like it. Not enough whitespace, too colorful.
I think it'd be better if the middle column was a scrollable list and the right column was fixed and display information when middle column boxes hovered.
Also, if I were looking for browser addons, I'd be looking for a "Chrome Extensions Center."
"Chrome Web Store" could mean many things. Web could mean anything so it should be omitted, and store is misleading if things are free.
Google had something like a Chrome Extensions Center before this but then added apps that you can pay for and started calling it a store. Apple's Appstore also calls itself a store, yet many of the downloads are free so calling it that is not misleading, at least in a new way. I imagine it is called a 'web store' since other stores tend to be either mobile (Apple, Android, ...) or desktop (Mac App Store, new Windows 8 Store coming next year) and it promotes the idea of a webbrowser being an operating system (albeit it is redundant).
I think it'd be better if the middle column was a scrollable list and the right column was fixed and display information when middle column boxes hovered.
Also, if I were looking for browser addons, I'd be looking for a "Chrome Extensions Center."
"Chrome Web Store" could mean many things. Web could mean anything so it should be omitted, and store is misleading if things are free.