As T-Mobile can't get the phone in till June, they suggested I go into Carphone Warehouse and upgrade through them and I can get the same deal.
Once I was in CPW they told me they could match the contract but I would still have to pay £99 for the phone. No way I'm paying for the phone (or going for a different contract) so looks like I'll just have to be patient and wait for T-mobile to release the thing.
Apparently T-Mobile are thoroughly testing the mobile to ensure the phone is ok to sell. Obviously not in a rush given every other competitor has it and there aren't any widely experience problems with the device.
Mate try Chitter Chatter (T-mobile vendors).