Microsoft has revealed that there will be no CDMA Windows Phone 7 devices this year. At first, reports started trickling out that Verizon, the largest US mobile-phone carrier as well as the carrier which helped Microsoft launch the failed KIN, would not be on board until 2011, as first posted by Bloomberg. After that, it became clear that CDMA was being excluded on the whole (the decision was made earlier this year but Microsoft declined to publicly confirm it until now); only carriers that use the GSM standard are being included.

Europe, where Windows Phone 7 is launching first, will be safe because it is dominated by GSM, while in the US, it looks like AT&T and T-Mobile are good to go (though it's still not clear if T-Mobile will have devices at launch), but Verizon and Sprint are not. Microsoft has said before that Verizon and Sprint are key Windows Phone partners, just apparently not in 2010.

"We had to make some trade-offs," a Microsoft spokesperson told CNET. "Even Microsoft doesn't have unlimited resources. We had to prioritize doing fewer things, really, really well. For the worldwide market, the vast majority of phones are GSM phones, so we focused on GSM first and then plan to deliver an update that will have great CDMA support in the first half of 2011."

The bad news comes on the same day of the final release of the Windows Phone 7 SDK as well as demoes of official YouTube, Twitter, and NetFlix apps. In order to reach a broader market, Microsoft will need to make sure that CDMA phones start trickling out sooner rather than later in 2011 if it wants to see Windows Phone succeed quickly.