I don't see what possible motivation Apple would have to make the web experience as close to native as possible. They don't get a cut of sales on native apps, and they can't control the content, style or functions to the same extent - are these issues not important to Apple? Seems they are from how they act about app approval.
Seems like a great way to ensure that the entrepreneurs making the next great web app support your device really well.
One unique selling point of both the iPod and iPad is their status as mobile internet access points. Cementing that status and encouraging entrepreneurs to pay attention with great web APIs seems like a natural way to extend Apple's developer base.
If I was addicted to some great web app and learned that it had a nice iPhone interface when I was on the move, I would be incentivised to invest in an iPhone.
