This is good news! Why? Well, 2 reasons:

Customers and developers alike have demanded this functionality, and Apple has seen the light. Applications that just run in the iPhone version of Safari was not going to cut it.
My new business can make use of this wonderful news in product development :-)

More details need to emerge before I get super-excited, like what will the developer limitations, if any, be? But I am a bit excited.

Some discussion has been going on everywhere in the blog-o-sphere. Example: Robert Scoble discussed this.