HP Slate, the iPad Rival, will be using Windows 7 on some Units

"The HP Slate will use Windows 7, but what isn't known is which chip will power the Apple iPad rival from Hewlett-Packard.

This is an important question, as there's a world of difference between an Intel Atom processor and, let's say, a low-power Core 2 or Intel's latest-and-greatest chips based on the "Nehalem" design, referred to commercially as the Core i3, i5, and i7. Atom chips (with one exception) use a single-core processor--which can struggle under moderate to heavy workloads--while the more powerful Core 2 and i series chips use two processing cores.

HP has been careful not to reveal the silicon inside. And the company has declined to answer queries about internal silicon specifics. So, let the guessing games begin." source