I've just upgraded to wheezy and my Canon LBP 7200Cdn stopped working. I used Radu Cotescu's script to try to reinstall it, but that failed and messed up apt-get, as one of his debs tries to install an outdated package. I've cracked the problems and got my printer working again. If anyone else is having similar troubles, you are welcome to get in touch and I'll give you the details of what you need to do.
Cheers,