It’s being reported that the Sony VAIO TZ (TZ11) Series will have both a traditional 2.5-inc spindle-based Hard Drive (up to 160GB) as well as a 1.8-inch 32GB Solid State Drive (SSD) (via Laptoping.com and Engadget). The TZ series has an 11.-inch display and weighs just over 2.6 pounds, and uses an Intel Core 2 Duo Ultra Low Voltage CPU.
In theory, you should be able to load the OS onto the Solid State Drive, and combining that with the Ultra Low Voltage CPU and the LED-backlit display, the battery life could very well meet the eight hours that has been reported.
Meanwhile, Akihabara News has an actual VAIO TZ and has published several pictures, with a review coming in the next few weeks.