N.C.
M.,
As an early childhood teacher, my opinion is that computers are pretty much an inevitable part of most children's lives, but they do not greatly enhance a young child's life, and can even hinder some social development. That being said, my own child does love the computer, and I have to limit his time playing games on it already (and he is only 3!).
There are some educational games and there is some merit in knowing how to use a computer, in my opinion, but it is not necessary in kindergarten. I strongly stand by the belief that kindergarten is ideally about strengthening social skills, physical abilities (gross and fine motor skills) and establishing a foundation for a love of learning that will last a lifetime. Computers will not necessarily be the door to open this key to education, but they can be a (small) part of it. Moderation is key.
One big hesitation I have about computer usage is that it can hinder creativity sometimes in young children. While I think older children can get very creative and innovative ideas using computers and the interwebs, younger children tend to get "stuck" sometimes if they use it too much. I have noticed this with children in my class - the ones who play a lot of video/computer games tend to play out the games with a very predictable and exact script, while children who don't play these games as much have much more creativity in their play.
Computers are great, but not necessary for kindergartners. Just my opinion.
Best,
Nessa