Very impressive showing by Ubuntu on the basic scientific use front. Octave is absolutely delicious in that you can just bloody do things. I *might* drop Scilab but Octave isn't quite so shiny on my Win7 lappy.
And of course, Scilab has an Ubuntu release that runs pretty well (once you get OpenGL working, of course.)
Don't get me wrong, there's still a small stack of stuff that I still can't get working under Ubuntu, but that stack is SHRINKING. And it's small enough now that I DON'T need Windows for everyday work.
Also, Ubuntu is totally rocking my sound card already. Bravo, Open Source, bravo.