HTC has planned a little get together in London on September 15. They will be announcing something, but are keeping very quiet about it. We think that this is going to be the official announcement for the HTC Desire Z and Desire HD. These are international versions of the G2 and the EVO. The art above matches up with images we have seen before of the HD. There is one thing in the picture that doesn't add up though. Windows? This little get together is awfully close to the launch of Windows Mobile 7 which is coming to Europe in October and the U.S. in November. Could we be seeing HTC phones with Windows Mobile 7? Mind you this is all speculation, but doesn't it kind of make sense?