thyde,
Many Best Buys and Circuit Citys have recieved them (and then sold out). Good Guys has received some and is apparently to receive many more in the next week. You may want to get on a waiting list at your area retailer, if they have one.
I would definitely recommend buying locally. I would also plan to have my off-air antenna at the same time when you buy; that way, in the event you can't reliably receive all the local HD channels that you want, you can return it. IMO, a HDTV Tivo is very hard to justify if you can't reliably receive your local channels in HDTV.