According to the Apple.com order page, when you pick even the most basic one (16GB Black iPad), you have to wait 2-3 weeks before it ships.
My co-author, Matt Miller, ordered a 32GB Verizon 4G model on March 7th, and I ended up pulling the trigger on a Wi-Fi 16GB on March 8th. According to my latest order history, it's still slated to deliver on March 16th.
If you're wondering why I bought a new iPad, and Wi-Fi only, it's actually for my family to use. I have an iPad for work and every time my family wants to use the iPad, I'm always concerned that they might mistakenly delete an appointment, or an e-mail, or an app that I'm testing for my day job. $500 is a small price to pay to make sure that I don't have to feel that concern anymore. I probably could have gone for the older iPad, but since the iPad is used for gaming most of the time in my house, I figured the bump in processor speed and Retina Display was worth the $100.
As for why I went with the AT&T 3G instead of the 4G on Verizon for my own use, I had a bad experience previously, where Verizon suddenly reported that I had used 1GB worth of data, whereas I have rarely gone over my 250MB allotment on AT&T. That alone was the determining factor, not to mention that I can easily swap out the SIM to the new iPad, so no contract change needed, and I can always connect to a 4G hotspot, if I really want the 4G experience.
Are you expecting your new iPad on Friday, too? If so, what made you buy the latest iPad over the previous generation?