Exactly. Also, as they are becoming more similar to Android, it won't take much for users to actually switch to it. I am sure Google is happy to see this development.
I don't think it's Android's busy, ... unique interface that keeps Apple owners from switching. It's the hundreds of dollars in apps they've invested in that won't transfer.
I don't know that that's true, I think it's general consensus that an android phone is not as good as an iPhone. I'd wager that this update removes a lot of that divide and gives people a reason to look at the alternative.
This is just speculation, I haven't run the iOS 7 developer preview yet.