Joomla 1.7 is going to be a relatively simple release with no big surprises.
One of the goals of Joomla 1.7 was to separate the Joomla Platform, (the Joomla engine), from the CMS itself.
The new Joomla 1.7 Platform includes many new features that will be of interest to developers.
One new feature is the integration of M17n into the Joomla 1.7 core to enhance Multi Language capability.
See how it works here.