ASUS is offering two different versions of the U2E. The A1B model is a more typical ultraportable notebook, equipped with a 1.8" 120GB hard drive. The A2B is identical in all areas except for the choice of mass storage. Instead of a traditional hard drive, ASUS includes a 32GB solid-state drive (SSD). That should certainly improve performance in disk intensive applications, but with the size of Windows Vista and modern applications 32GB can fill up very quickly.
Check it out over here, the reviewer claims the U2E may very well be the best ultraportable currently available.