Where most time-based distributions have a schedule of round and about six months, Debian takes another approach, obviously because Debian is more about stability and longevity than about the latest and greatest features in each release. As such, the project adopted a two-year release schedule, with a development freeze every December of odd-numbered years, with the actual release following in the first half of the following year.
The first of this new type of freeze will happen December 2009, making the time between the current release and the next one rather short - this is a one-time occurrence. "To accommodate the needs of larger organisations and other users with a long upgrade process, the announcement reads, "the Debian project commits to provide the possibility to skip the upcoming release and do a skip-upgrade straight from Debian GNU/Linux 5.0 (Lenny) to Debian GNU/Linux 7.0 (not yet codenamed)."
Despite the relatively short development time, the next Debian release, codenamed Squeeze, will still have some interesting features, such as multi-arch support, which will make it easier to install 32bit packages on 64bit installations. It will also sport an optimised boot process which will reduce boot times and improve reliability.