Yes, it comes with a p2p SQL server and readable namecoin domains. Due to BitTorrent it's also much faster than Freenet. While it doesn't require Java it's still crossplatform.
Sites are essentially bitcoin addresses (public keys) with ownership and modification rights controlled by corresponding private key. The same crypto provides passwordless logins and authentication!
Since it supports Tor, users can also use it anonymously.
Depends - it should win out for speed and ease of use. But anonymity, no, in order for a user to possess certain content, they have to download it explicitly and know they're sharing it. It's trivial to know who visits a given website and, for example, send DMCAs to all of them. Freenet prevents this in multiple ways - proxying your connections through others and using encryption to prevent those without the keys from reading the data or even knowing what it is. Freenet probably provides the best anonymity of any current network as it's done in such a way that once a file is on the network, there's just no way to trace it back to its source.
The people using Play on it might find themselves in some fun legal issues soon, depending on country.
You could use it over Tor I suppose - that's what the authors propose, but that seems less than optimal to me and doesn't even approach the sort of anonymity Freenet could.
Looking at it briefly, Tor support is a bit misleading. It only protects content authors and seeders, and not viewers. (Someone could just inject an external image reference to reveal their true IP address as HTML seems to be not sanitized.) This seems to be the key difference from Freenet.
Well, that's an easy fix - view the page in the Tor browser too. Or better yet, run the whole rig inside a VM which is forcibly routed over Tor transproxy. Of course - this is sort of Tor abuse and freenet is the better solution for this purpose, but if you need to view something over this in (relative) anonymity, it is still possible.
Sites are essentially bitcoin addresses (public keys) with ownership and modification rights controlled by corresponding private key. The same crypto provides passwordless logins and authentication!
Since it supports Tor, users can also use it anonymously.
The system is impressively elegant.