I went cold turkey on Opensuse 10.2 few years back, with KDE 3 (still prefer it) I never even booted into a Windows OS for a year and a half. Now-a-days it's about 50/50 with the rigs I have dotted around, but I still prefer linux as a desktop. I also love getting my hands on an old "slow" PC and bringing it back to life with a fast lightweight linux distro.