What performance upgrades iPhone5 have?

It’ll have a faster, probably dual-core processor, plus more memory and an improved camera -- one that might be able to take 8 megapixel still pictures and record 1080p HD video. You’ll be able to play more realistic games, switch between open apps more quickly, and keep more web pages open at once.

Beyond that, you can bet that Apple doesn’t want a repeat of "Antennagate," and will be paying special attention to the iPhone 5’s antenna to make sure there are fewer connection issues.