Yeah these machines are finally available but they have some drawbacks that I have been reading about at: http://forum.eeeuser.com/
For example the systems cannot use a journaled file system because it will wear out the HD too fast.
They also do not have swap partition for the same reason.
The consensus is that if Asus can cut the sale price in half then it would worth it to purchase one of these machines. However, for about $100-200 USD more you can have a similar machine with a traditional hard drive.