I was told the same thing. The rep told me that if you upgrade to 4g...you are signing a new contract and all terms apply (including data cap regardless of whether using 3g or 4g. However, she did assure me that I could get a new 4g capable phone and activate it on my current 3g unlimited plan...and as long as I do not renew my contract...I will keep my unlimited. Since there is no date for 4g in my area...I am thinking that is what I may do. Although I am tempted to get a new 2 year contract this week and either the Droid2 or droid 2g so I can have on more early upgrade come Feb of next year...and then once the Atrix comes to Moto (assuming nothing better comes along before then) I might just dish out the $$$ for it without a contract.