Cor Bosman wrote: 
RC is not a playground anymore ( well, it may still be playing, but  
with the big boys now :) .
    

We run it in a production environment with over 50,000 accounts (the  
other 800,000 are still on squirrelmail) and about a 1000 concurrent,  
but i do realize we're taking a risk. I wouldnt use it if i didnt  
think it was ready for this, but at the same time, i know it's still  
only a 0.x release.
As a maintainer of a similarly sized RC installation, I'm OK with parts of RC still being a bit of a playground.

The core architecture is very good, but there are several areas which will take more time to flesh out.  I'd rather go through the pain and confusion of shifting apis than slow down the rate of change.  At least for the next few releases.

Best,
Ziba