Toshiba's introduced the first notebook with a 512GB solid state drive today. The 12.1" Dynabook SS-RX2 weighs in at just over two pounds and measures just 25mm thick.
The MacBook Air's stirred up some interesting discussion about what's expected of an ultraportable notebook. Lenovo's answer is the ThinkPad X300 series, which features a 64GB solid state drive, three USB ports, a DVD burner. Not bad for a 2.5 pound package.