Officially, Dell hasn't revealed a release date for the 10-inch Windows slate, which it announced last February, but who says the tablet won't arrive until the fall. A September launch could jeopardize "back to school" sales, but it may not matter because Dell is positioning the device as "business-ready."

Though it's not clear why the Dell tablet will take so long to arrive, a late launch isn't a big shock given the tarnished history of Windows 7 slates so far:

* HP's Slate 500, in early 2010, launched as the following fall.

* Lenovo scrapped its plans to build a Windows 7 tablet in October 2010. "The challenge with Windows 7 is that it's based on the same paradigm as 1985--it's really an interface that's optimized for a mouse and keyboard," Howard Locker, Lenovo's director of new technology, said. "It has to be optimized for touch."

* MSI announced the Windows-based in May 2010, but its release plans are still unclear. A report from October said the tablet would , following the launch of an Android tablet in March But then said the Android tablet won't arrive until May or June, with no word on the Windows-based WindPad 100 at all.