I recently put my blog on the .onion. You can get to it via the "normal web" via it's .com address, via google searches and whatnot, or you can use a .onion address to get the same stuff. I have to say, it was pathetically simple to set up, and I encourage everyone with a server of their own to do the same. Feel free to upgrade to a Tor relay if you have bandwidth too.
You may well ask what's the point? Well, my motivation was to see how easy it was, and to increase the amount of content available on the .onion network. I'm pretty sure the only people who've ever visited it are me and one friend of mine, but the fact there's another IP on the internet talking to Tor nodes, and the fact that on very rare occasions those Tor nodes talk back to it makes me feel good.
If ever I have too much spare time, maybe I'll make a search engine for .onion addresses...? ;-)
Back on topic: the Silk Road had a restrictions policy (albeit an inconsistent one), but other people have no such qualms. The authorities have succeeded in one sense in that they've fragmented the market, they've also put some additional risk onto the purchaser because it's now less clear how legit the site or vendor are. However, they've enabled someone looking for something minor like a bit of weed to also find all manner of other things. I'm sure someone looking for an RPG would have found one with or without the SR, but someone looking for weed might start thinking "I could also buy an RPG", where they might not have done before. In that sense, shutting down SR was a failure.
Ultimately, if there's a demand, there'll be supply. Shutting down websites of any kind doesn't alter demand very much, and so there'll always be supply. If the authorities wanted to do anything about this, they'd spend more time working on the demand side of the problem. Sadly, that doesn't have instant results, doesn't get headlines and for every success it has there's a notable failure too.