Pidgin 2.4.0 was released back in March with a number of new features, but replacing that this week is Pidgin 2.5.0. This update delivers a number of new features such as the ability for libpurple to create custom emoticons, SSL certifications support to the NSS SSL plug-in, the MSN protocol is updated to version 15, MSN offline IM now supported, Finch improvements, and there are many other changes...
To get a package into Ubuntu, you have to be friends with MOTU's if you want it ever in. Same with Debian. And to update a package, it either has to be a security fix, or you wait 6 months until the next release.
So getdeb.net is there for new / updated packages. For updating packages, they base the .debs off ubuntu ones (even keep the credits), so the 'quality' is the same. For new ones, it's pretty good too, as the process receives QA before publishing and etc.
Anyway, there's nothing wrong with my pidgin, so I'll patiently wait for a proper backport of the next pidgin release to Gutsy, where/when ever that is.