I've noticed a fair amount of annoyance, frustration, even outrage over the artless inclusion of John in that "One Laptop per Child" commercial. The main points of contention go as follows: a)it's of questionable propriety for the ad to have words come from John's mouth which he never uttered; b)on a related note, who knows if John would have consented to this; c)the impersonation verges on comically poor; and d)it's curious that Yoko would choose this cause over others that focus on more pressing concerns.
I would say it's not especially productive to speculate on how John might have felt about this particular campaign. Even Yoko couldn't know. And if it's in poor taste for the makers of this commercial to put words into John's mouth, then so it is for overzealous fans to proclaim what his opinions might have been (though I recognize the considerable disparity in scope and content between each side's agenda). Thus I find much of the disgust that's boiling on the web to be misplaced and overwrought. It just strikes me as a petty battle.
However, I do agree that it's beyond tacky for the commercial to insert a contrived voice track into the video footage of John and act as if it's actually him speaking. And yes, the impersonation is cringe-worthy. And yes, the rhetoric "John" employs seems a bit extravagant for the cause ("You can give a child a laptop. And, more than imagine, you can change the world").
In my view, a more sensible approach would have been to include an authentic audio clip of Lennon extolling progress, peace, change, etc. and then play that to images of children with their laptops. Obviously an explanation of the campaign would also have to run, but I can't imagine it would be difficult to skillfully incorporate that around John's part.
A commercial of this kind would still likely arouse resentment among the Lennon faithful. But at least it might avoid the charge of having appropriated John's visage for such phony and tactless results.
(If the embedding is disabled, go here).