Windows Phone 7? What's that? Do we need this?

So, what's the purpose of the new type of mobile phone? Don't we have enough phones on the phone market? Does somebody loves to get used to new mobile phone? What the hell?

We already have a lot of phones which fits our purposes very well. We have this nice iPhone with a huge amount of apps. We have "Google phone" for those who is not addicted to Apple's production. All this Simbian, RIM, Windows Mobile ... Oh, god of the mobile phone market, tell me please if there is a room for the one more phone and a mobile OS?