The thing these programs [try] to bring isn't so much help with learning as much as EQUAL ACCESS to learning. It attempts to level the playing field between the kids at home with no pc for research and the more well-off kids with greater tech access.
That said, it doesn't provide in home internet access, satellite or 3g coverage, so many times it seems like a wasted effort, but it allows students greater flexibility than previous generations. They aren't tied down to a classroom, or getting shuffled out of the lab so a new class can come in. They can do their work anywhere there's free wifi. Further, it adds a value to your district in less tangible ways: showing kids you trust them with not-inexpensive hardware does interesting things to their psyche.