Windows RT is Microsoft's first OS for ARM processors, which are found in Apple's iPad and most Android tablets. Analysts say RT is targeted at consumers and will attract a new generation of users with little ties to PCs, much like the iPad. The OS will come preinstalled on tablets and differ in some ways from Windows 8, which is considered a successor to previous Windows operating systems.

"People should play with them in the store to see if the device is right for them," said Dean McCarron, principal analyst at Mercury Research. "We have a new device class, a new architecture, and people need to figure out how it fits with their device usage model."

Here are some things to consider when looking at RT tablets:

Windows RT or 8?

Microsoft has engineered Windows RT for touch, Internet connectivity and long battery life, and some tablets highlight those features. Windows RT is viewed as more of a tablet OS in the mold of Apple's iOS, while Windows 8 tablets may appeal to PC users looking for backward application compatibility. The cheapest RT tablet is Microsoft's Surface, which starts at US$499, while Asus' Vivo Tab RT starts at $599.99. Windows 8 tablets are competitive on price, with Acer's new W510 tablet priced at US$499 with an Intel Atom chip code-named Clover Trail.