According to the post, those iPads are chained to desks in windowless rooms. Among the lucky few companies to actually be able to test their iPad apps are Major League Baseball, The Wall Street Journal, and (of course) The New York Times. While the iPad's form factor is perfectly tailored for reading ebooks, Amazon and Barnes & Noble have both had to develop their iPad apps without the benefit of trying them out on a working device.
The article notes that with the iPhone, some of the earliest developers with products to market have become the most successful. That's the reason that so many developers are working on customizing their iPhone apps for the iPad. However, the developers also understand that making a misstep with a new app that hasn't been properly tested can kill any chance of success.
Panelfly, for one, isn't taking chances with their comic book reader for iPad. The Times quotes PanelFly CEO Wade Slitkin as stating that "As much as we'd love to be there on Day 1, a misstep could kill the train before it even gets out of the station." On iPad launch day, it will be fascinating to see who is in the race for the long run, and who jumped the gun with poorly-designed apps.