You hear of very few people who've had an iphone that don't like them/give them up* is all I'd say.
*if you have, can you explain why, without any anti-apple comments? Would really appreciate any honest answer to this...
I got rid of my iPhone. I had a 3G on a really good tariff (£15p/m for the £40 o2 iPhone tariff). Didn't want to 'upgrade' to iPhone 4 as that would have put me back on stupid tie in, and wasn't bothered about paying £500 for it.
Then actually when I started looking pretty much most of the use of the apps was at home instead of getting the laptop out. The apps that I did use I could get on pretty much every other platform.
That swayed it for me to get an iPad as a phone/laptop replacement around the house.
Phone wise I plumped for a new windows phone. I'd had some windows mobile phones before and being a developer I had written apps for WM. Curiosity got the better of me in how dev is be on the new phones. Didn't fancy Android, have though it about it but it just seems still too raw at the moment.
I was actually getting a bit bored of the iPhone as well. I don't like how there's in integration between apps, feels disjointed. Just time for a change.