entropy functionality

I see a new feature and tweaks in my system regarding entropy.  My reading 
of /etc/rc.d/random tells me that both are loaded if both exist and the 
rc.conf variables are anything aren't set to no.  What is the difference 
between entropy_file and entropy_dir in rc.conf?

Is -current still the appropriate place to talk about RELENG_5?

Thanks,
Jason C. Wells