I've been covering various ultrabooks recently including Acer, Toshiba, Sony and others. I was never impressed with Dell's design of ultrabooks. Recently, Dell just announced a new XPS 13 ultrabooks that looks promising.
Ultra-thin design. Thinner and lighter than Asus and Macbook Air at 12.4 x 8.1 inches. Acer Aspire Ce is 12.75 x 8.5 inches and Macbook Air is 12.8 x 8.94 inches.
About 9 hours of batter life. Loaded with I7 processor.
What else you need?
Lol!