Been getting ready to get the next iPhone to upgrade for my girlfriend's good oooold HTC touch diamond white (one of the most beautiful phone back in the days, and still rocking with it, I know I know, but can't convince her to get another new phone just coz she likes the white so much), was gonna buy the white 4 for her but it came out so late so might as well wait for the next iPhone.
If the next iPhone will be the same appearance as the current version, will probably end up buying the 4 with iOS5 installed. iOS5 will be a huge update to my black 4, so no need to get the next iPhone personally.
Camera upgrade? nope, rocking with my Canon 7D if wanting to take more serious photographies. 4 already has the quality for everyday needs. Megapixel doesn't mean better pictures.
A5 chip upgrade? nope, iPad 2 in hand for bigger screen with better performance on everything.
Slightly bigger Screen? nope, same reason, "iPad 2"
what else is there to upgrade from the 4 if the form factor is gonna be the same? RAM? I don't know, can't think of anything. like i said, iOS5 is going to make the 4 awesome enough. (can't wait for the "+" button to be the shutter for camera, LOL, funny that every single phone that i used to owe had the shutter button for camera, now i get a little excited for that particular function, haha

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From having 3G, and had absolutely no intension at all to upgrade to 3GS. but the 4 made me go out and line up 2 weeks after the 4 was released.
so my hope is that they will come out with 2 models
iPhone 4 8GB just black or just white
iPhone next gen black and white 16GB & 32GB.
Fingers crossed (C'mon Apple, let me spend money on ur next iPhone)