Defying logic, enterprise users flocked to Windows Mobile 5 in droves during the first quarter of 2007, despite the announcement that Windows Mobile 6 would be available in the second quarter. The PDA market actually grew 40% compared to the year-ago quarter, fueled by strong WinMo5 sales.

Usually the opposite happens. When a platform upgrade is imminent, people refrain from making new purchases until after the upgrade is available. Not so with Windows Mobile, according to data from Gartner. PDAs running Windows Mobile experienced a 64% increase in sales, and pushed the overall PDA market to reverse trends and see 39.7% increase on 5.1 million units shipped.

Microsoft-based devices represented 3.2 million of the total, or 60% of total PDA sales. Gartner does draw a wavy line in the sand, however, when it comes to the definition of a PDA or smartphone. In fact, the line is downright blurry, with devices like the Nokia E61, Motorola Q falling into the PDA camp and devices like the Palm Treo 750, RIM BlackBerry Pearl falling into the smartphone camp. Pots, cauldrons, kettles, they all serve the same purpose, if you ask me.

Funky definitions aside, Microsoft's achievement and gains in the market are notable. Can the Redmond Team keep it up? It will be interesting to compare sales of Windows Mobile 6-enabled devices for the rest of the year to the first quarter WinMo5 numbers.