It's been a while since I've installed Linux. I burned the 10.4 Ubuntu Desktop (386) CD and overwrote my 9.x partition. The install went well. No issues with WiFi connecting by default (and my WEP key is sticking).
It automatically migrated my "My Documents" files from Winders during the install (but I rarely store stuff there).
It's trivial to access the NTFS partition - it mounts automatically when one starts browsing there.
And Wine works very well. E.g. I can run the Windows GUI for gnuplot without too many issues (but will install the linux counterpart soon), and it runs Excel, PPT and Word from Office97, (even file browsing inside Office) so I'm Ok there, too.
I'm very impressed with how well it's working so far.
We'll see how it goes.
Cheers,
Scott.