"The release of Ubuntu 11.04 has seen the arrival of a new look and feel for Ubuntu. A whizzy, new launcher and dash, and a clever workspace manager are some of the biggest changes. Take a look at what’s new and then feel free to choose between the classic and new desktop experiences at login."
The system requirements are undemanding, but, given my previous experiences, I'll decide for myself if 384MB of free RAM is really all you need to run the new system! However, there is little doubt that this release will get a run-out over the next few days on the Inspiron 1501.
Sources & References:
Ubuntu 11.04 What's New?
OMG!Ubuntu! Natty Guide
Ubuntu Wiki Natty Narwhal Release Overview