On Thursday night, we started generating localized nightlies on Aurora. The builds are posted here:
As part of the whole new rapid release cadence, the Aurora builds are “string frozen”, so localizers can safely use these Aurora builds when localizing the Firefox5.0 release. If you see any problems, with any of these localized builds on Aurora, please let me know, or even better, please file a bug.
For the curious, here’s what the Aurora about box looks like for Spanish (specifically es-ES):