What does Att have to do with anything? And that droid x does not use more, the droid,and mostly all smart phones can use that much. 3G is going to stay unlimited.
I'm not sure where in any part of the rumor you're getting the notion that 3G data rates will stay unlimited, but Verizon's LTE 4G network is still in the fairly young stages to continue to offer unlimited data rates for the multitude of Android phones on their network. The Droid 2 is apparently slated for an August release. I believe Verizon is just too big a network to continue to offer unlimited data for all these media rich smart phones. The only reason Sprint offers unlimited data is because thats the only way they can still compete with the bigger players of AT&T and Verizon.