#3 is a given. HTML5 is great for cash-strapped companies that want to achieve the cheapest way to have their product function across multiple platforms.
A company w/serious coffers like Facebook, native apps PLUS HTML5 are their calling.
Argument 4 is exactly what I thought when I read the title. What an idiotic statement to begin with - who the hell bets on HTML5 based on Zuckerberg's statement towards its usage in Facebook?