Following HTC, Samsung and other mobile phone manufacturers, Nokia is rumored to be announcing a series of phones running the Windows operating system at the Nokia World Conference in London Wednesday.

The Windows OS, Mango, has yet to really compete against the likes of the iOS 5 and Android. But if the world's largest mobile phone manufacturer does indeed announce the launch of Windows Mango-ready phones, the market for mobile operating systems could go through a major overhaul in the coming days.

Recent industry reports show Nokia not doing too well. It is already phasing out the Symbian OS, and the MeeGo was short-lived. The only feasible option to revive its image, it seems, is to work on through the Windows OS and look to create a phone with design and specs that appeals to as many people as possible.

According to an interview given by Microsoft CEO Steve Ballmer last week, Nokia could unveil a bunch of Windows phones at the show. The probable sets are the Nokia 800, which is codenamed Sea Ray, the Nokia Sabre and the Nokia Ace and Microsoft's Windows Phone BFF.

According to Gartner analyst Michael Gartenberg, there are a number of variables to consider, when speculating on what Nokia will show at the conference.

The most important thing for them is - whatever they deliver - to deliver in a timely manner, and show how they can differentiate themselves in the marketplace, said Gartenberg.

As far as the launch date of the Windows phone is concerned, experts believe Nokia will not hit the U.S. market before 2012. The company is still looking for an advertising agency in the U.S., as historically the country has been a weak market.

But Nokia does have a marketing strategy planned for European consumers and should launch its first Windows phone in the EU,  a market that has always proven more receptive of their handsets. The decision could backfire, though, as all the latest online services and apps offered by Windows phone will work much better in the U.S. In addition, Microsoft does not plan to update Mango OS in the near future; or at least to the extent of improving service in other countries.

Nokia may be playing to the holiday season by stocking their new phones as early as possible. The delay of a few months could prove to be a problem, particularly for a company that is now trying to prevent its market share from further eroding.