If you want an iPad, get them when they're in stock. Apple still run out of certain models from time to time. The demand has just been crazy.
And now, it looks like iPad sales will accelerate simply because there isn't no alternative at the moment with the strength of the hardware, software, and the whole ecosystem.
Honeycomb tablets like Samsung's Tab is very good but it lacks the backing and mind share of the average consumer. HP's Touchpad is selling out because of a $400 price drop down to $99.
A lot is counting on Amazon to stop Apple or at least slow down the iPad.
The bottom line is this: the iPad works. It simply does. And its has a lot of apps to go along with it. And unless someone can some around and provide the same experience, Apple's iPad will continue to flourish, whether there is competition or not.
Furthermore, don't hold your breath for an iPad. I've said this before. Apple is just keeping up with demand now. There is no need to push out iPad 3. They'll likely save all that excitement for 2012 when Apple's competitors renew their assault on the tablet market. Joining Android will be Windows 8 tablets.
However, I still am holding out hope that we'll see a 5-7" iPod touch.