If an IP hosts multiple sites, you'd need to figure out the correct http HOST header to send it, unless you're use a static IP for every site. Most web hosts are using name-based virtualhosts: https://httpd.apache.org/docs/2.2/vhosts/

We implement both name- and ip-based vhosts, but only for sites with dedicated IPs (read: sites that need a dedicated IP for SSL.) You can do SSL on a shared IP, but it gets more complicated. Cloudflare does it by using a cert with multiple "certificate subject alt names", but security / site spoofing would still be an issue if you're ditching SSL at the same time (which would be a good idea).

This is the /real/ web 2.0...maybe even web 3.0: peer-to-peer hosting without ICANN or Verisign and co. We can do it, and people are working on building it right now. Reddit has Meshnet and NameCoin seems like a good idea. Now we just need a similar solution for SSL and a good way to host/update things. The future looks bleak for ISPs, CAs, registrars, and non-free countries.