after getting back from PDC last week, i can tell you that sharepoint developers implementing web parts now is a *good* thing. after seeing whidbey at pdc, an interesting roadmap emerged with regard to web parts, asp.net 2.0 (whidbey) and windows sharepoint services. web parts is a core technology in the next version of the asp.net framework...providing a “portal framework” technology.
good news: all web parts currently developed for wss will continue to work under this framework!
better news: web parts developed under whidbey will work in wss!*
there is a slide deck presentation from pdc that you can download...i encourage all to check it out...email me offline if you can't find it.
*might require a service pack to wss