The most remarkable thing about my transition from Windows has been the non-event aspect of most of it.
On Windows I was a die-hard Emacs, Thunderbird, Firefox and Open Office wonk. Now that I'm on Ubuntu, I've switched to, um, Emacs, Thunderbird, Firefox and Open Office.
I have a big fat 250 Gig Western Digital FAT32 filesystem on USB that I can bob easily between Windows and Linux.
I've auto-mounted my Windows partition for ease of access.
Most of the things I've plugged into my ThinkPad T42P with Ubuntu booted have "just worked".
No messing with video drivers or network cards or any of that. I can browse my Windows network neighbourhood and generally just get stuff done without thinking about the fact that I now have an immeasurably larger toolset at my disposal than I had on Friday.
The Gnome desktop is servicable and pretty enough for my largely non-taxing GUI needs.
I got Java + Jython set up without hassles. Python is all over the place on Ubuntu. What's not to like?
At last, I have a laptop setup with some very, very serious headroom for software development.