While we may look at the iPad as a portable computer or a large cell phone, the reality is different. To understand the iPad, you need to know that Steve Jobs has more of his personal wealth tied up in traditional media companies than in Apple stock.
The iPad is a device to help consumers purchase media provided by large corporations.
That is also where the other devices are going: allow consumers to purchase media. Games are media, not software. That means that in the Apple line, the software market is not significant and never will be.
I just read a "Business Insider" column mentioning that many of the Fortune 100 companies are buying iPads for evaluation. That is a non-issue. In my experience, those companies buy tons of devices for "testing" that they never put into production. There will be a number of niche companies that will use them.
If you want to have a business selling mobile software, don't focus on a specific mobile device. Instead, build a network of people who can write such software and sell to businesses that think that they can use the devices in their network. Almost nobody will be able to make a business on just one platform (until such time as a consensus emerges as to a "business platform").