Now, Windows Mobile has been passed by the iPhone in smartphone OS marketshare for the first time according to market research firm comScore.  The comScore data is collected from monthly surveys of thousands of customers in the U.S., asking them what phone they own.  The results are averaged over a three month period.

Analysis on the latest three month average, which ended in October, just wrapped up and the results have been aired.  They show RIM advancing its lead with about 14.96 million customers in the U.S.  Considering that RIM started the year with less than 10 million customers, this is an enormous success story and a testament, among other things, to the success of Verizon Wireless's buy-one-get-one promotion on Blackberry smartphones.  In total, the numbers indicate that from the start of the year to October RIM grew almost 55 percent in terms of units on the market.

The iPhone, likewise, has earned some bragging rights by stepping up to second place with approximately 8.97 million users.  Apple's growth is equally impressive when you consider that the first average of this year, which ended in February, showed the iPhone with only 5 million users -- that's a growth of approximately 70 percent.  This indicates that while both RIM and Apple are enjoying terrific growth, the iPhone's market share is growing slightly faster.

The news isn't so pretty for Microsoft, which fell to third place.  The Windows Mobile maker actually saw a slight contraction, with numbers slipping to around 7.13 million users. Microsoft was hurt by the fact that many customers don't want to get a Windows Mobile 6.5 phone when Windows Mobile 7 will be arriving in 2010, bringing with it significant improvements.  Microsoft also is having a tougher time finding its role amidst the emerging iPhone (fun) and Blackberry (business) duopoly.  It is significant to note that Microsoft was the only major phone OS maker of the six in the study to have lost marketshare in the period ending in October.

As for Android, Palm, and Symbian, all showed modest growth.  Android finally cracked the million mark, weighing in with 1.02 million users.  Palm, boosted by the Pre and new Pixi, showed about 2.484 million customers in the final period of the year and Symbian had 1.3 million users.

Overall, the smartphone market continues to grow.  According to the survey, an estimated 36 million Americans (11.8 percent of the total population) own a smartphone, while 196 million Americans (64.4 percent) own a traditional phone.