I've been hearing a lot of buzz about Windows Mobile 6. In particular, the improved mail client (which features flagging, HTML mail, and some other Exchange 2007 goodness) is something I'm eager to get my hands on. Lots of folks are wondering how they can get Windows Mobile for their existing devices. The answer: a resounding "it depends."

The bottom line: mobile operators (they hate to be called "carriers") will ultimately decide which WM6 devices they'll offer. Device OEMs like Palm and HTC have access to the WM6 bits, and they can certainly create builds that include the drivers and other phone-specific bits. However, they won't do so unless there's carrier demand. For example, T-Mobile has already promised to release WM6 for its Dash smartphone, which is a rebranded HTC Excalibur. Why aren't there updates announced for other HTC-manufactured phones? Because Verizon, Sprint, Cingular, Orange, and other MOs haven't decided whether they will offer them or not.

MS is often unfairly blamed for this situation, but it's not their fault. They make WM6 and release it to OEMs and operators, who then decide what they'll release and when. The operators have to get FCC certification for their phones, which is expensive. Given the choice between spending the money to recertify (say) the Palm Treo 700w with WM6, or to certify a brand-new Palm device, most carriers would probably choose the new device because it helps drive customers to them.

So, if you're wondering whether operator A or phone B will support Windows Mobile, it's too soon to tell in most cases, except for the following:

• if A=T-Mobile and B=Dash, then yes
• if A=Cingular and B=iPhone, then no