Some? I think we can expect to see a lot of switching to iPhone. A recent survey showed that one of the main reasons people switch to Android was the larger screen sizes that were available.
For sure, myself included. I switched to a Nexus 5 when it came out last year, but by January I had switched back to iOS because I could say without any doubt that I had a strong dislike for Android. Of course I said some because the majority of people don't switch phones until their contract expires, so someone who got a GS4, for example, may not immediately be in the market for a new phone.