Microsoft's (Nasdaq: MSFT) Windows Phone celebrates two small victories this week. Although the struggling operating system still has a ways to go before establishing itself as the third major mobile phone operating system, it seems to be gaining traction.

First you get the developers, then you get the apps
A new survey of 2,160 developers by Appcelerator and IDC found that the number of respondents who reported being very interested in developing for Windows Phone rose 8 percentage points year over year to 38%. The increase makes Mango the third most popular OS among developers, replacing Research In Motion's (Nasdaq: RIMM) BlackBerry OS, which lost 7 percentage points.

The survey also found that a plurality -- 48% -- of developers cited Microsoft's partnership with Nokia (NYSE: NOK) as the reason for their increased interest. This was driven largely by international interest. In the United States -- where 31% of developers are very interested -- most cited potential integration with computers and tablets powered by Windows 8.

It's worth noting that Apple (Nasdaq: AAPL) iOS has 91% developer interest and Google (Nasdaq: GOOG) Android has 83% interested. Also, being very interested doesn't necessarily mean the developer will actually make an app for the OS. Many will probably wait to see if Windows Phone manages to gain traction. However, the fact that an increasing number of developers are taking the OS seriously is a good sign.

Lumia lights up
On the more concrete front, Nokia has reported that pre-orders in the U.K. for its first Windows Phone, the Lumia 800, have been greater than any other Nokia smartphone to date. Some of the excitement might be related to the discounts and bonuses U.K. retailers are offering to draw attention to the phone. For example, U.K. wireless provider Orange is offering customers a free Xbox 360. You could probably argue that this is cheating just a little, but given Android and the iPhone's dominance, Microsoft needs to leverage every advantage it can.

The question remains whether the Lumia 800 will make the same grand entrance in the U.S. when it launches sometime next year. Microsoft has already begun its marketing push for Windows Phone, while AT&T (NYSE: T) has begun offering a selection of slick Mango handsets from Samsung and HTC, including the budget friendly $49.99 Samsung Focus Flash. However, no handset has emerged as Windows Phone's must-have device. Nokia's arrival could create the splash the OS needs to gain traction.

Foolish takeaway
As I sad at the beginning, these are both rather small victories for Windows Phone, but they indicate that the OS is starting to move in the right direction -- albeit very slowly. Now Microsoft needs to continue to market the operating system aggressively and keep the momentum building.

If you would like to keep an eye on Windows Phone's struggle to gain market share, consider adding Microsoft and Nokia to your free watchlist.