Yea - looks that way. 3.6-3.7 are just security enhancements, under the bonnet stuff.
http://www.neowin.net/news/main/09/12/28/mozilla-pus...
To hold users over until the completely revamped Firefox 4.0, Mozilla will continue working on the release of Firefox 3.7. It's currently due sometime in 2010 and is expected to include the following features:
* Overall better performance
* 25% reduction in startup time
* Jetpack (new plug-in interface, easier and no restarting needed)
* 1st stage of Electrolysis (moving plug-ins into separate process from main browser)
* Weave (bookmark, password, plug-in, and open tabs synchronization)