It's a cool idea and personally I don't think they can succeed by competing with other conf call providers with just this feature. It takes lot more to compete with the rest.
Having said that, I thought many times that WebEx should provide an option to automate simple tasks and this was one my wish list. Right now WebEx gives an option to create incoming call but the user need to login to the WebEx and create the callback. If the meeting admin/owner can initiate the call automatically based on the time that'd be really great.