I've been using it for most of my reading (newspapers, books, magazines). A lot of my surfing and a lot more video consumption than I had expected.
The sketching apps are great. I bought a little stylus to help out where fingers fall short. I'm doing a lot more drawing than ever b/c of the facility and convenience of drawing on the pad.
The comic book readers are great (I use comic reader mobi). I hadn't read a comic or graphic novel in years, but they just looks so gorgeous on the ipad that I've been voraciously catching up on various comics that I would have otherwise ignored.
I find myself using the iphone much less when at home and the laptop has been relegated to "work"/upright/serious stuff.
iPad, for me, is something of a leisure computer. If that makes any sense...