Ars Technica posted their impression from the Windows Phone 7 launch event in London

At the Windows Phone 7 launch event in London today, all four (or five, depending on how you count) UK networks had a presence, as did Samsung, HTC, and LG. All three companies will have handsets available on October 21st. Relative cellphone newcomer Dell will also have a handset available at launch.

Across the world, HTC announced five handsets: HD7, 7 Mozart, 7 Surround, 7 Trophy, and 7 Pro. The HD7, 7 Mozart, and 7 Trophy are launching in the UK on the 21st, and the 7 Pro should arrive early next year. Company representatives said that the final phone, the 7 Surround, may or may not see a UK launch.

The HD7 will be exclusive to O2, the Mozart will be exclusive to Orange, and the Trophy will be exclusive to Vodafone. HTC gave no indications of which carriers would receive the Pro.

  Feature: Windows Phone 7 London: a few first impressions