These types of things are already available (and I would wager much more stable than the type of thing found in PPA's) through third-party repositories like http://Dotdeb.org
Honestly I think PPA's only real-world appeal will be for desktop Debian users.
No one with any rational thought process is going to use a PPA sourced package on a server environment.
PPA support would just make it easier and safer to add repositories like http://dotdeb.org to your setup. I don't see how PPAs are any worse than manually adding entries to your sources.list file. They're almost the same thing, except the former a bit more automated.
Honestly I think PPA's only real-world appeal will be for desktop Debian users.
No one with any rational thought process is going to use a PPA sourced package on a server environment.
edit: missing closing parenthesis.