Woogle RC2 has been successfully tested recently with MediaWiki versions 1.15.3, 1.16.0b2 and 1.17.0alpha (r63248). Prior in development, Woogle was running fine with MW 1.11 and beyond. For details see our Compability compability notes
This is the first public beta of Woogle. We consider the basic functionality rather stable, since we are using Woogle internally for around 6 months now.
Beware that some cleanup and especially a detailed check for security issues is still todo, while intial checks have been done already. However, be careful when exposing Woogle on public sites at this time. Use of Woogle on your own risk.