Pretty much, there's a new retention device so you'll have to buy a HSF specifically for AM2 unless you use stock, but I've heard that some people could still use there 939 HSF on AM2.
Its the only main difference worth knowing. It is also good to know that it will be easier to upgrade with AM2 in the future. When skt 939 is discontinued it will be hard to upgrade, this probably wont be for a while though.
anyways... i'd wait for conroe (comes out july 23rd), or K8L in 2k7
even when conroe is released it will be much better to buy an AMD because they'll drop in price by a lot.