I have 2 books, 22 apps, couple of pdf's, one movie at 1.23gb, about 11 email accounts and I have 4.5gb left on the Fire.
But I do have lots of content I can stream from Amazon, Netflix and my NAS.
I would have loved them made it 16gb or even just added a SD slot. But the price likely would have been increased to 225 or 250. And to some that 199 price is a buy and anything over 199 would hesitate some consumers.
Here is a what the Fire is likely to have cost/BOM.. $143
http://www.eetimes.com/electronics-news/4230653/TechInsights-says-Kindle-Fire-BoM-about--143