Seems like good old GSM is refusing to disappear. An enhanced flavour of EDGE announced yesterday (27th March 08) by Nokia Siemens tweaks the potential data speed of existing EDGE networks to a usable 592 kbps (presumably in lab conditions though).
This only requires a software upgrade to existing Nokia Siemens installations so could be deployed quite rapidly.
Whilst not on par with HSPA networks (3.5G) it does exceed the original 3G data rates, with potentially many more handsets upgradeable to use it.
Further improvements up to 1.2 Mbps are promised.
The original iPhone could be around longer than expected.