IGonz said:If you're with AT&T you keep your unlimited.
I just bought my iPhone 5 two days ago at AT&T and kept my grandfathered unlimited data. Even kept my 200 text for $5/month.
AT&T even unlocked my 3GS over the phone today.
I'm curious, how much are the texts if you go over? I have a teenage daughter; on a slow month her text count is 10K. We have the unlimited text/talk plan.