Today is the day for the iPhone SDK:

At this point, it's still not clear whether Apple intends to officially release the SDK at Thursday's event or just make some announcement. At any rate, the SDK will be in programmers' hands soon, and analysts and developers expect a wide variety of applications to blossom in the coming months -- everything from photo-editing apps to motion-sensing games that take advantage of the device's orientation sensor.

The possibilities, as Mac developer Daniel Jalkut recently noted, will be limited only by developers' imaginations.

Those possibilities will be also influenced by a number of outstanding questions about Apple's planned app-distribution method, the vetting process it will use, and any iPhone access restrictions the company imposes on developers. The company is expected to provide answers to those questions as well on Thursday.

Even more important though:

At the very least, Thursday's SDK event will involve an announcement about new enterprise features for the iPhone, according to an invitation circulated last week.

While enterprise software may not be as sexy as movie and game apps, its inclusion could be huge for Apple's ability to meet its goal of 10 million iPhone sales by the end of the year.

By adding features like push e-mail and cultivating relationships with corporate-software vendors, Bajarin says, the iPhone could become one of the major communication platforms in business, making it much more competitive with the corporate-friendly BlackBerry.

Read more @ Wired News.