From a primary ICT teachers point of view I agree with jmak, the kids need to see ICT as tools not treats (our school is not there yet, iPads have not been in long enough!). They should experience all OS, a range of software and hardware. Life does get more complicated as you add more systems and devices and I like to wait a while until somebody comes along with a minimum fuss, workable solution. We run a CC4 network and I have only just purchased iPads because I needed to be convinced that they would be able to work together and upload/download work from one to the other without the trouble of synching to a Mac or using Dropbox (we are using Foldr and it's working well for us).
I agree that tablets have their use but cannot replace other laptops or desktop machines. It's about mixing and matching to suit: In Yr 3 this week we started to look at programming. We talked about algorithms using real life examples, then we used A.L.E.X the robot app on the iPad to grasp sequencing (they can walk around with the iPad checking they have the turns in the right place). We then went on Enchanting Enchanting : Enchanting : Enchanting on the computers and used it to program the Lego Mindstorms robots. Enchanting is just like Scratch, which they already know, and maybe a bit easier for the little ones than the NTX software. Fitness for purpose is the only way.
Longer term I would love to bring in Picoboards or Maky Makys, Minecraftedu (there are excellent teaching resources for this) or maybe some Raspberry Pi's (need a lot more convincing about their educational value before we go there though). I also need more time to play and a money tree at the bottom of the school field.