Granted, there's no easy way to do it by default, but if you don't mind installing Stylish, which you should anyway, and aren't scared of a little CSS, it's child's play. If you feel the new tab page needs a little push, there's one way to liven it up, add a background. So long in fact that when it finally arrived, it was a bit underwhelming. Plenty of others have been waiting for it for a long time. Not everyone likes it and plenty of people simply chose to disable it.
The new tab page is one of the big new additions in Firefox 13.