See the product site at http://www.dellxps15z.com/. I am a big fan of 15" screens.
I'm quite with my XPS 15, but I can definitely see the allure of the 15z. Mine is a bit chunky, which is only made worse with the 9-cell battery.
Finally somebody got it right. A thin, stylish PC. Keep it up Dell, perhaps others will follow suit. I have a dream that, perhaps, one day, nobody will have to look at the ugliness that is Thinkpad.