A friend of mine had an iphone 4 (as did his wife). He's a photography geek too (meaning he buys and sells cameras all the time). When he saw my lumia 800 he started to think about switching, when he saw the WP8 and 920 events he was really considering it. I told him about the kid's corner feature and he loved that idea.
He has a developer account, so he got the ios 6 update on he's iphone 4 a while ago and said the maps were crappy
Still, the day the iPhone 5 pre-order was up, he ordered it.
Now, what does it mean? is he too scared to try something new? happy enough with the iPhone despite it not being a big upgrade?
If the 920 was available, he might've went into a store to look it, or maybe pre-ordered it to try it out. but it's not and no one knows when it will be available, how much it will cost and which carriers will have it.
I'm sure the fact that the Lumia 920 was announced got some people to wait, but most of those buying the iphone as soon as it's released or in the first month were never going to get a different phone. The only think Nokia achieved is that their phone is compared to the iphone everywhere and usually favorably.
Most of the buyers don't buy the iPhone when it's just released. They're not crazy fans, they're not loyal and when they're contract is up, if it looks like there's a better device out there, they might switch to it instead of getting the new iphone