If you are an Ubuntu fan and have tried different variations of it., you will like the new Ubuntu light. It is designed for instant usage and boots up at 7 seconds(on a Dell 10v with SSD). It is unlikely that it would be slower than 20 secs for the current generation of PCs.
According to Canonical, Ubuntu light will be totally different from Netbook Remix. Ubuntu light targets people who want to send emails and update status messages in a jiffy without the need to open up a full blown OS(Windows, Ubuntu or any of the lot).
This new variant will be perfect for facebook users who just hang around the site chatting up friends and do not need to run any other applications.
for a detailed analysis please visit Mark Shuttleworth