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.

HTC's lineup

As is going to be a recurring theme with Windows Phone 7 handsets, the phones were more similar than they were different. The HD7 had a glorious 4.3" screen, and the Mozart had an 8 megapixel camera. Aside from that, there was little to significantly differentiate the models. All of them felt solid, though the two smaller phones felt uncannily light.

What HTC does do to differentiate is bundle applications. Each HTC handset is preloaded with a bunch of HTC-developed custom applications. There's HTC's now familiar weather software, a post-it note-taking program, audio and photo enhancing programs, and a stock ticker program. All can be pinned to the home screen, or accessed via HTC's hub application.

Apart from apps, another area that the hardware companies can differentiate is the camera application. Though the basic operation of the camera is standard across all the phones, companies can add their own effects and processing; for example, they can offer different metering modes, ISO ratings, or autofocus modes, and they can include special effects. HTC, for example, has a solarize feature.

HTC's phones all included Dolby Mobile and SRS Surround audio processing, which should in principle make them better for listening to music and watching videos than any of their competitors.

LG is launching its Optimus 7 exclusively with Vodafone. There was no word on whether the 7Q—the same phone but with a hardware keyboard—would launch, or if so, when it would launch.