I've been waiting for this to happen for years.
I thought of this idea over four years ago and hadn't heard any of the big phone companies talking about it until I read this news article today. I guess it's no wonder they didn't want to talk about it too much. The idea is long overdue, with only one problem - mobile calls are getting cheaper and cheaper to the extent that, at times, it is cheaper to call using the mobile network than the land line. Nevertheless it's an excellent idea and I have no idea why it hasn't been implemented sooner. I will be looking with great interest to see if it comes to Australia soon.
This quick Q&A gives a good summary (although some of the questions/answers are a little dodgy).
Is a little concerning. I would have structured the service in a slightly different way. The handset itself should be a stand alone mobile with a separate phone number to the land line. People calling someone with this service could then make the choice whether to call the land line or the mobile (and have the relevant rate applied). This configuration makes much more sense to me but I'm sure it has its own issues. For example the phone companies would then no doubt charge two line rental fees (one for fixed and one for mobile).