The iPad is due to come out on or around March 29th according to Steve Jobs at the iPad Keynote.  AppAdvice is saying that Apple will begin taking preorders for the Wifi iPad beginning February 25th.  There is not much reason to doubt the rumor as it fits within about a month of the upcoming release for the Wifi only model.  For those of you who want the iPad with 3G you will have to just wait around for your preorder as the availability is still uncertain.