Infoworld points out the obvious - handhelds are a niche market. The problem is simple - these devices are neither fish nor fowl, and people can already use their cell phones for all the things a handheld promises. Once you've covered address book and email, you've covered most of what people want to do with these devices. There's a similar issue with tablets, IMHO. Now, if the hardware cost of tablets equalizes down to the level of a standard notebook, tablets may become ubiquitous... but it won't be because people are actually looking for a Tablet. It'll be more along the lines of "oh, it does that too? Cool".