The iPad is a great tool for consumption of information but without a practical keyboard not information production. This does not diminish its usefulness but rather frames the situations where its value is greatest.
One question many have asked is where does the iPad fit in the technology ecosystem? Will it replace laptops, netbooks etc? My answer is no primarily because it is focused on information display and does not offer external ports (USB, display, etc.). Thus, it will likely be a popular add-on or niche device.
With this in mind, the iPad has value for both consumers and businesses. For consumers, it is an easy to use attractive device for reading books, surfing the web (with the big exception of Flash), watching video and managing email. For business, it is an ideal device for one-on-one sales presentations and sharing a portfolio of work with clients and prospective clients. For both it offers Apps for almost any need and connectivity where ever you may be.
In summary, the iPad has value and will be successful. In addition, it has raised the standard for slate computing which should drive competitors to offer more user driven devices with greater, more accessible functionality.