The launch of Apple's iPad is bittersweet for Otto Berkes, a Microsoft manager who led the company's earlier effort to develop a handheld, wireless, touchscreen slate computer.

Microsoft's "Origami" project surfaced in 2006 and gave early definition of a new category of devices between phones and laptop computers. It led to the Ultra-Mobile PC category that never caught on after early models were priced over $1,000 and the device was caught in the Windows Vista turbulence.

Berkes, who now works in Microsoft's entertainment and devices group, shared his thoughts on the iPad on his personal blog, where he said the iPad is nicely designed but won't be the last word on the slate computer. He also posted a photo of Bill Gates displaying a handheld device in 2004 that points toward yesterday's arrival of the iPad.

A few tidbits:

Apple gets credit on execution and good packaging of available technology. That said, their thin slate is an unsurprising product in the context of an evolutionary timeline that spans decades of innovation and effort chasing the slate computing dream.

On the size of the iPad:

As a device, the iPad seems somewhat large and ungainly to me. With the 7"-display-based Haiku/Origami, I aimed for greater mobility in the tradeoff between mobility and display real estate. Not having a way to write on a pure slate device the size of piece of paper also seems pretty unnatural to me. One of the iPad demos shows a legal-pad background for note-taking, but then you have to use the on-screen keyboard. Say what? There's a real cognitive disconnect there. Of course, display size is highly subjective (hence the many variations in laptops) as is the relative importance of stylus functionality for different users and uses. There is plenty of room for continued development of and innovation with the slate form factor, and it will be interesting to see how the industry responds to Apple's interpretation.

UPDATE: Here's a video with Otto outlining the history of Microsoft's ultra-mobile PC effort: