I was just playing around with my phone and tried a trick and it worked.
If you want to get on Vodafone 3G even before it gets officially Launched, here is how it works
For Prepaid: SMS > ACT 3G and send it to 144
For Postpaid: SMS> ACT 3G and send it to 111
You will be charged as per your current 2G plan for now.
Remember this trick is exclusively brought to you by us.