I recently added more RAM (4G) and a new HD (320G, 7200rpm) to the 1201N. This required re-installation of Ubuntu 9.10 Karmic onto the 1201N. The installation went without a hitch- I had previously re-installed Window 7 Professional, and Ubuntu went in and found it. Ubuntu also correcly detected the 4G of RAM and install the PAE kernel, which allows the use of a 32bit kernel with the extra RAM.
The PAE kernel is working fine with the Nvidia ION drivers, suspend and hibernate.
I found more information about a wifi driver, and this post at the Asus forum has links to an actual Linux driver. Using this driver doen’t require the NDISwrapper, but I have noticed that the wiki will not re-connect after suspend, which the NDISwrapped, Win2K driver did. However, I’ve been hibernating (due to the bad batter life on the 1201N) and the wifi works fine after a hibernate wake-up (which is decently fast, especially with BootBlaster for the BIOS).
The opening of the 1201N to replace the hard-drive is a bit more than just opening a panel in the bottom, but it’s fairly easy, given you take your time in cracking all the little pressure-tabs which hold the top and bottom of the case together. The new HD and the extra ram are making Ubuntu much more responsive and snappy.