Microsoft CEO, Steve Ballmer, has officially launched Windows Phone 7, and is keen to stress that the new operating system is quite unlike anything else already on the market:

"We have built, with our partners, a very different kind of phone," he said at the company's US press conference.

"We've focused in on how real people use their phones. We set out to design a phone that was really modern."

"Everybody should be able to look at a Windows phone and say 'I can represent me in this device'", he added.

He also announced that one of the launch handset partners, in the US at least, will be Dell. The manufacturer joins LG, Samsung and HTC, although there are currently no indications on whether the company will also join the bandwagon in the UK from 21 October.

Certainly, no European carrier has announced a Dell WP7 handset yet.

UPDATE: We've just had confirmation that the Dell Venue Pro handset is exclusive to T-Mobile in the US.

UPDATE 2: Sources from within Microsoft have just confirmed that the Dell Venue Pro is also expected to hit the UK sometime in the near future. No further details are know at the moment, though.