RE: I pad vs kindle fire
I personally think Apple are way too restrictive over how you can use the stuff you've bought (apple devices only). Fine if you have bought into the whole Apple eco-system type thing and have invested a lot of money there, but not so fine when there is so much choice available.
Obviously the Kindle Fire will centre around it's Amazon shop, but it niggled me a bit that they (supposedly) aren't allowing access to google play. While I will normally harp on how wonderful Amazon is, that bites a little. Also no GPS was the final decision maker for me.
Google/Asus Nexus 7 on the other hand has the GPS I so badly wanted, it has access to Google Play (and £15 free credit to start you off), and I can access the Amazon app store, no restrictions. Amazons free paid app of the day is a little hit and miss, but we have had a few.
No doubt there are other app stores around, but how many do you really need?
Battery life is a shocker after the Kindle, a few hours use and it needs a recharge, but it does depend how you use it.