as long as its a 4.8inch screen that has the ability to have at least an additional column of icons, and not just an iPhone with fisher price huge icons this will be superb once developers update the apps to support the new resolution.
downside, all apps get bigger as they have to hold the new graphics for yet another resolution of iPhone, and apple stubbornly refuse to stop selling the 14GB model (Apple, stop selling your iDevices using HDD sizing, or actually sell 16GB of space, its annoyingly penny pinching things like this in a supposedly high end device thats starting to get you a bad name, my Galaxy SII when empty actually has 16GB of space as advertised)
Plus side, unless apple cock-up by making it as thin as a human hair, battery life might actually last a day, something that the iPhone has been unable to achieve since the iPhones initial launch.
My plan is currently to upgrade to the samsung galaxy note 2, its the perfect sized device, and i just wish apple would converge the iPad mini and iPhone into a device the same size so i didn't have to either carry both a Phone and a tablet around, or use the joke OS called android, but id rather have a clunky, buggy OS and a single device that does everything i want, that fits into a pocket easily, the iPad mini is still just too large to be a device i can carry everywhere, so the note 2 is replacing the need for a kindle/iPad by it size, but means i don't need a phone as well.
Apple choice is clear, it needs a bigger iPhone to stop androids constant cannibalisation of its market share (especially outside the USA), but 4.8inch might be to little, to late, it needs to suck it up and get the iPhablet out ASAP