I own a Mac Pro, an iPad and an iPhone. I don't own a laptop because, frankly, I'm not mobile enough to need one. If I need to do something quick like email or check something online, the iPhone is more than capable.
The iPad usage will be about 99% in-home, or if I go on vacation where a traditional laptop would be useful to have. The Mac Pro is still the main machine where I do most of my work, but for casual web browsing, the iPad is being used more and more. I'm not that much of a gamer anymore, but there are some great games on the iPad that are quite addictive (Plants vs. Zombies, anyone?)
So yes, the iPad really fits in well as a casual laptop replacement - bigger screen than an iPhone when you want to surf or play games (and I'm sure you could use Skype, but the iPhone app is perfect - feels like you're making any other phone call.)
The iPad really is more than an oversized iPhone, as much as the haters would like to disagree.