Phonegap sort of sucks. When you create an app with phone gap, it's laggy, the swipe transitions are jagged, and it images don't load quite properly.
I don't think Phonegap support is an acceptable solution for cross platform. Nor do I think the Adobe flash compiler to iOS and Android is.
Why didn't Microsoft build a transcoder for WP7 and WinRT that transcodes objective C and the iOS SDK API and map methods to it's framework?
Does it really want people to spend all that time and money to rewrite iOS apps?
With a few small tens of millions of dollars in work, you could automate 80% of that. Does Microsoft want "somebody else" to do it?
"Hey, you know what?"
"somebody else gonna do it any damn way"
They won't, and if they do it's not going to be funded properly and it will be horrible. It would probably take about 10-20 million dollars to do it extremely well, and that's chump change for Microsoft.