ICAAN, the body responsible for the administration of the domain name system has recently approved a recommendation to use 'generic domains'.

At the minute, there are 21 generic Top Level Domain names (TLDs)  with a further 255 country specific TLDs (as of writing). From January 2012, you will be able to create your own TLD- eg you could have a .black doman and create the website www.myke.black or even have a domain name that has no extention eg www.mykeblack. Registering your own TLD is not cheap, it's going to cost $185,000 (plus $25000 annual fee) so it's likely that only big businesses will be using them eg www.itunes.apple or www.search.google or possibly profligate local councils.

This is going to be bad news for web applications that use a TLD lookup to verify email addresses or web addresses as being valid. Also, there are issues of trademark protection and public perception. If you see a web address that doesn't conform to the normal pattern, eg www.seo.seo then people might unconsciously distrust it, and thus lower the click through rate for such addresses.