We're big fans of Ice Cream Sandwich (Android 4.0 to the rest of you), but right now it's only available locally in the form of the Galaxy Nexus (and apparently random updates on the Nexus S). Vodafone is offering an email update service that will let customers know when ICS is made available on the phones it sells.
The email service will send updates relating to both new Ice Cream Sandwich models and updates to existing devices. It won't actually get you the updates any faster, but it does mean you can hang back and await notification that your handset is getting an upgrade.
A quick check on Telstra's updates page shows that it has one ICS upgrade scheduled right now, with the HTC Sensation seeing the new software in February assuming testing goes OK.