It does make you wonder about Apple's commitment to supporting HTML5 web-apps. When they were an underdog it made sense, but now that they're in a position of strength you are relying on their good will, not their self-interest.

After all, if you read through Gruber's piece on the change, everything he says applies just as much to HTML5 webapps e.g. no lock-in, lowest common denominator, vague sense on non-nativeness etc.

He specifically says "There is no platform vendor for the web — and Apple has complete control over WebKit, its implementation for the web." but that could easily become the Adobe Flash or Microsoft line of "Standards bodies move too slowly for us".