> Running Retroshare over Tor has a number of definite advantages: it does not require firewall management (Tor does it for you); you do not need a DHT to find your friends (Tor does it for you), and whatever code is tied to ensuring security of your IP information is not needed anymore.
For what it's worth, they've provided a version that can use Tor for a while now. What's new is that the provide a portable version that ONLY uses Tor. Pretty handy!
I guess the idea is rather than a user@host identifier, that looks up via first dns, then at protocol level on the host (eg look up mx record for <host>; attempt rcpt to <user> via smtp) - or a dht protocol - one could simply use a tor node identifier as user identifier. Which might make rotating keys hard - but at least that makes sense; onion "addresses" are unique and "secure".
> Running Retroshare over Tor has a number of definite advantages: it does not require firewall management (Tor does it for you); you do not need a DHT to find your friends (Tor does it for you), and whatever code is tied to ensuring security of your IP information is not needed anymore.