At some point Apple will make the iPhone 802.11 N 5GHz compatible. Do you think it will be this upcoming release? Seeing as the iPad2 has it I would think so.
The 2.4Ghz spectrum here in the UK is pretty crowded, so although the 5Ghz band doesn't necessarily offer a speed increase as such, the 5Ghz band is 'less cluttered' shall we say.