Not from a chrome extension, as those are browser-centric solutions (not webpage-centric).
Niklas Von Hurtzen has created a very useful js extension called html2canvas that essentially does what you're looking for, just not as a chrome extension. You can see it here.
Once "rendered," the plugin will create a canvas element by traversing the DOM tree of whatever you hand to the extension. From there it's pretty simple... yourRenderedCanvasElement.toDataUrl()
will return a data: URL representation of that canvas element, which by default is a PNG, giving you a "screenshot."
Edit: Ha, I see now that you reference this exact thing in the message thread in the other answer...