Latest release:
KDevelop 4.3.1
Apr 19, 2012 (KDE 4.5 or higher)
KDevelop 4.1.2
Jan 14, 2011 (KDE 4.4)
More:
There are two active mailing lists for KDevelop. On one hand, there is the User list, which is aimed at support and general discussion around KDevelop. Furthermore, there is the Development list. Here all important discussion around future development of KDevelop takes place. If you want to start contributing, you should at least follow the latter.