Tempera (and our other settings-based themes) have pretty much reached their feature and functionality maturity and we consider them stable.
We are now updating them only when necessary to fix identified bugs or improve compatibility with new WordPress releases.
Nowadays we’re constantly bombarded with update notifications and everything is constantly getting a new release almost daily. Personally I don’t like this and feel that nothing is ever properly tested any more. Software done right and working doesn’t require constant modifying and changing – that only adds to the uncertainty factor.