So it's not a full-blown SDK for iPhone, but it's more than a list of website bookmarks, too. Rather than reinvent the wheel yet again, creating yet another SDK for developers, Apple is leveraging existing Web 2.0 expertise and providing a stripped-down SDK that allows phone calls, emails, and maps locations, and possibly more. All of this before the first ship date of June 29!
Steve Jobs has gone from saying that no third-party development will be allowed to saying that third-party development will be allowed using a limited but powerful development environment. While disappointing to some who had built up high hopes on a foundation of no evidence, that's progress. Does it put the iPhone behind competing smartphones with full SDKs? Maybe. For certain types of apps, almost certainly. Time will tell how much of a disadvantage — or advantage — the limited development options actually are. For now, we can only wait for the details to slowly slip out from under NDA, and see what developers manage to produce.