This week, there are two conferences being held. One is Apple's Worldwide Developers Conference, which sold out for the first time this year. The other is Microsoft's TechEd IT. Apple's announcement of a new iPhone, one that appeals to IT departments, may leave some mobile IT aficionados thinking they went to the wrong conference.The iPhone has been out for a year, but at its introductory price point it was clearly just a geek status symbol. The price has been coming down, though. This week's announcement that the price of the 8 GB iPhone 2.0 is only $199 really takes the status out of the symbol, bringing it into reach of just about everyone. The other important development was that the new iPhone has connectivity to corporate mail systems, bringing it into serious competition with BlackBerrys and Windows Mobile phones.

When the iPhone first came out, Steve Ballmer savaged it, and he identified its weaknesses well. But most of those limitations are gone now, and the phone that has entranced consumers is now threatening to eat corporate market share. In another April 2007 interview, Ballmer said, "There's no chance that the iPhone is going to get any significant market share. No chance." He may need to re-evaluate that opinion now.

But the sentiment out of Redmond is still relentlessly upbeat; Robbie Bach, president of Microsoft's entertainment and devices division, says Microsoft Mobile phones will thrive against the BlackBerry and the iPhone. Yet I don't see how this could be true in any universe. For one, they're saddled with a Windows-like UI, which seems clumsy compared with the elegant iPhone interface. For another, they're trapped in the OEM model where they don't even control the final product. A mobile phone isn't a shrunken desktop; the model that served Microsoft well for PCs isn't ideal for mobile phones.

The BlackBerry and Windows Mobile devices distinguish themselves by having their tiny keyboards, which makes them great for some users and applications. But there's a price to be paid for all that keyboard space, and it's the small screen size. Apple picked a different trade-off: lose the hardware keyboard but get a much bigger screen. The on-screen keyboard requires a deft touch, but then again so do the tiny chicklet keys on other mobile phones.

Most of all, the iPhone's touch screen makes mobile browsers easy enough to actually use, and it's already accounting for a disproportionate amount of Web traffic, considering its market share. Can Windows Mobile create a Web browsing experience that's anywhere near as good? It's going to be tough.