I've heard that Windows Phone 8 has been confirmed, but I'm interested to know when we will see phones with Windows phone 8 installed?
Offical statement is that it's going to be released later this year (2012). All Windows Phones running WP7 will not get the update to Windows Phone 8. Instead they will receive an update to Windows Phone 7.8 which includes some features (e.g. the new home screen) but not all the WP8 stuff.
Windows Phone 8 will be released on October 29th 2012. Phone availability depends on your region*, but you will start seeing them early November in most locations. The first phones available will be the HTC 8X & 8S and the Nokia 820 & 920.
*For example Singapore gets the HTC 8X on November 7th.