Have you thought about a Asus UL30A-A1? It's a 13'' notebook, still very small, and with better battery life. You can get one cheaper (under £400) than a Asus 1201N. If you don't plan on needing Ion platform (3D stuff).
3 gigs of memory, plays HD stuff, bigger screen, bigger keyboard, same resolution, dual core processor.
Asus makes good netbooks as well, the EEE PC line.