It's also worth noting that 02 are doing nothing new or discriminatory here - they are treating their iPhone customers in exactly the same way as other customers at 02. The iPhone IS worth the wait, it's significantly faster than the outgoing 3G handset, and is the best in its class for what it offers. If you want one, you're going to have to wait, just as if you had another contract with another handset.
Of course, the other option is to download V3.0 software on your existing handset - it's a free upgrade and arguably more important than simply buying the 3Gs