First up: the freebie. Since the iPad supports the open standard epub format, we had assumed that there would be some way to get public domain books onto the device--and a screenshot of the iBookstore confirms that not only will it be possible, but, as reported by AppAdvice, Apple is simply popping the free catalog from Project Gutenberg into the store.
The rules for public domain books typically require 70 years to have passed since the author's death--but that means there's a huge supply of classics, about 30,000 in total, available for free. The books available range from The Iliad to Sherlock Holmes to Great Expectations, and would be a good way of hooking customers on the idea of reading books on an LCD screen. They'll try out a Dickens novel or a quick Sherlock Holmes romp, and hopefully find that ebooks are to their liking--which means they'll start spending on newer works.
Moving from the "completely plausible and almost certainly true" rumors to the "well, maybe..." rumors, the same source also captured an image that suggests certain bestsellers, perhaps the top ten or top 25, will be available at a lower price--$9.99, to be exact. That doesn't sound like that big a deal, since the most expensive books in the iBookstore will only be a few dollars more, but that $9.99 marker is the same price as books in Amazon's Kindle store, and one of the Kindle's biggest advantages. This is unconfirmed, but it'd be a shrewd move--and would effectively remove even one more advantage the Kindle has.
And finally, we were wondering how the iPad-specific apps to come would be differentiated from the usual iPhone and iPod Touch apps--after all, the iPad can run just about any iPhone app, but not vice versa. It turns out developers will typically use suffices like "HD" (despite the iPad being not, in fact, HD) or "XL", the latter being the most accurate. But aside from that, these "XL" apps will simply not display in the app store when viewed by an iPhone or iPod Touch--much the same way Android's app store works (if your phone is incompatible with an app, you just won't be able to find it).