I don't think the pre-installed apps take upto 10% of the space but you will have to read various views on blogs and youtube for an answer to question. But i found the local store in my region helpful while search for information as regards the ipad2 and other apple products.
Note: This post was edited by forum moderator to edit out promo link which is prohibited in these forums. on 03/28/2011 on 10:04 AM PT
I am looking to get an iPad 2, but I have a couple of questions. First, I was wondering how much disk space is on the iPad 2's drive. I know that the iPad 2 comes in 16, 32, and 64 gigabytes of storage, but how much of the disk is taken up with the pre-installed Apps (PhotoBooth, FaceTime, Safari, etc.) and iOS? Lastly, Will there be any cases (Non-Apple) that will use a magnet to put the iPad to sleep and cover the back? Thanks in advance!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic