URL regexes which were already broken from the beginning...

Indeed. DNS names without dots have been used for decades in intranets.

However what it resolves to depends on you search domain. If I shared http://www on twitter everyone would most likely see a different site. People should really be using http://to. to avoid conflicts with internal servers called 'to'

Not to mention http://museum

No, even worse. They broke many of them... and people won't know which until they are bitten.