Oh my GOD.....couldn't you have searched the already 47,364 threads already existing on this EXACT same question?
NO ONE KNOWS. There's your answer.
Actually the answer is very widely known...
NO
http://bit.ly/jBK1F
First roll outs of 4G will happen in 2011, but it won't really start to happen until 2012.
EDIT: Unless the iPhone is available on Verizon, which will have 4G starting in 2010. AT&T's exclusivity on the iPhone expires in 2010 also. So this is very possible