It certainly makes sense to think before changing your OS! ;o) Just to elaborate a bit more on what i have personally learned, Xandros seems to be a distro kept alive for the sole purpose of shipping Eee's with a very-legal free OS, but the user and developer base is so small that you shall not expect it to work very well, and the updates are indeed rare.
As you are new to Linux, another thing is worth to note: you can keep your home folder which contains most of your personal application settings (including for pd) and set up your new Linux which will then use these settings. Linux is very modular, and changing one part (e.g. the kernel, or the window manager) does not necessarily affect the other parts. The list of installed apps, and most system-level settings are not conserved however - the first can be saved and reloaded another way, the latter is not really necessary unless you are running a server.
With ubuntu, the non-free (gratis, but not open source) elements become available with adding more repositories, first of all Medibuntu.

Andras