For those of you who follow the InfoPath blog, this won't be new information. (It was posted here: http://blogs.msdn.com/infopath/archive/2004/11/17/258868.aspx)

I have a webcast on the 29th on create custom controls using InfoPath via ActiveX.

I won't be covering ActiveX itself, but will go over the various things available to ActiveX control writers who want to write a control for InfoPath.