Hmmmm. I'm not sold. It's like a gameboy idea but for younger children? I am not really in the market for ever more convenient ways to put them in front of a screen when they could be doing other things. I think no.
My dd's had a Leapster 2 each last Christmas (They are 3.6 and 4.9). They do play with them, probably a couple of days a week for 30 mins or so.
All the games are educationally based, some have basic maths, some letter recognition, some are opposites or memory games. There is also a drawing function which dd1 uses most.
The reason we bought the Leapster is because they have the learning path system where you can hook it up to the internet and see what progress your child has made and what areas they are improving in. You can also download games from the site for free such as Letterpillar and print off award certificates.
There is a wide selection of games from about 3 up to 10ish, I think, with different characters such as Nemo, Star Wars and Dora the Explorer.
We are happy we bought ours but dd1 now wants a ds like her big brother so not sure how long they would keep an older child interested.