iPad – great for consuming media – reading, watching, browsing all good. Crap at creating it – not great of remain, poor for tying anything decent, can’t really edit well on it etc. Cheaper though, and with 3G it’s better when around and about.
Laptop – fine for consuming and creating media. More ££, less good when really mobile.
Summary: if you have a laptop already get an iPad. If you don’t get a laptop. the 13″ Air is a good machine.