According to various websites and sources, (it is rumored that) Apple might be launching its latest product, iPad, on February 25th. This will be pre-sales for US customers only and will feature the iPad Wi-Fi version.
According to Steve Jobs, when he said iPad will be available within next 60 days, I think you should be able to get it before March 25th, which means that pre-sales and order bookings have to start as soon as this week.
Appadvice.com is pretty sure about it as they indicate that they have heard it from a very reliable source.
3G version is scheduled to launch after the initial Wi-Fi iPad but you never know when Mr. Jobs decides to give it all to the customers.