Thanks for noting this.
That is indeed a problem – it looks like the new PPA specifically does not deliver packages for maverick, though I’m not sure why: there are packages for Natty and for the older Lucid, but not for Maverick.
I’ve updated the post to instruct people to select Lucid, which I think should work, but I have not tested this procedure for a while and I’m currently lacking resources to do so. So if you guys have any comments on improving the process – I’ll do so with pleasure.