Mozilla have just released a series of updates for its products. These are security and stability updates and do not offer new features.

Firefox 1.5.0.12 - This is expected to be the last release in the Firefox 1.5 series.
Firefox 2.0.0.4
In the next few weeks it is intended to switch on the option to allow people to use the built-in auto-update system to upgrade from Firefox 1.5.0.12 to 2.0.0.4

Thunderbird 1.5.0.12
The next version of Thunderbird 2 (version 2.0.0.4) has not yet been released.

SeaMonkey 1.1.2