I have previously written about the possible use of Tablet PC's in an educational environment. It's then a natural progression to give the newly established tablet market a consideration as well. They have some of the same advantages as Tablet PC's, but some obvious restrictions as well.
Tablets have no keyboard. As obvious as that statement is, it's necessary to state it. The majority of people use a pen for writing on paper, and a keyboard for writing on a computer. In an educational environment, input would be a problem while using a tablet. While it's true that notes can be taken using the virtual keyboard, or possibly freehand using a finger or capacitive stylus, these don't seem to be viable options. If the precision of stylus use on a capacitive screen increases, which I hope it does, then my view will change. Until then, I can't imagine people being expected to use it for writing purposes.
I do, however, see obvious strengths in it's other features. They are small, and easily handled devices. More so than a tablet PC. Although not 'optimal' for reading on compared to proper e-readers (using e-Ink), it is fine for any purpose one would usually use a computer for. This gives access to dynamic webpages and apps specialized to teach specific subjects and lessons.
I can also imagine a type of use in the classroom similar to the use of Classroom Presenter, where students can view and manipulate slides right from the tablet, and hand in responses for immediate evaluation. And obviously, it can be used for electronic textbooks. The majority of tablets come with an ereader built-in for just this purpose.
Today's tablets are getting interesting. Although there is a way to go before these are optimal for a classroom situation, they are becoming more usable. With the right software in place, they have no problem becoming a valuable tool. Keyword being software. Without proper software, tablets in the classroom will just be yet another distraction. Throwing hardware at learning doesn't make people learn. But if its use is planned properly, it could be an invaluable addition to the classroom.