Lets be honest...about 90% of the new iPhone "apps" are web pages we've never heard of. That's why I think we're particularly vulnerable. Again, it would just take someone creating a semi-popular new iPhone specific web "app" to get iPhone users rushing to their site.
You are absolutely right! Until they fix I definitely have curbed my iPhone web apps use. There is absolutely no way to validate the reputation of many of these sites and people are giving them their yahoo, aol, facebook, etc. passwords right and left. Not to mention the exploits.