The dimming didn't work well with X-10. Plus they're rather [link|http://www.smarthome.com/903233.HTML|pricy].
I'm considering [link|http://www.smarthome.com/whatisinsteon.html|Insteon] to replace the X-10, have been waiting for the toggle switches, which I see they [link|http://www.smarthome.com/prodindex.asp?catid=103|finally have]. I think the dimmable CFL will work as expected with it since Insteon uses both powerline and RF to transmit the commands.
Damn - the toggle switchs are $46 vs $19-46 for the decora style. Think I'll wait a while longer.