Can I keep my unlimited data plan on the iPhone 4 with AT&T?

AT&T is launching two new iPhone data plans to replace the unlimited data plan.

If you're an existing iPhone customer with the unlimited data plan ($30 per month) you do not have to choose one of the new plans. You can keep your unlimited data plan on the iPhone 4 if you wish.

The new monthly data plans are DataPlus (200 MB for $15) and DataPro (2 GB for $25). An option for tethering is available but requires the DataPro plan and costs an additional $20 per month.