Gravity Forms v1.6.6 is now available via automatic update and the downloads page of the support site. This is a maintenance release that resolves minor bugs and issues that are primarily encountered in very specific use cases. That being said, we still recommend all users update as soon as possible as it's important to keep your plugins and WordPress installation up to date.
For those wondering when the next round of feature enhancements will be released for the core Gravity Forms plugin, we have an assortment of Gravity Forms goodness in active development. Gravity Forms v1.7 will be the next major feature release and more details will be forthcoming as it's development nears completion. Stay tuned!