Is a quad core cpu WORTH it in a laptop?

I'm looking into buying a new laptop. The large majority only offer dual core cpu's. Some manufacturers offer a quad core option but they are either drastically more expensive or are close to a ghz slower. So I ask the community;  What are your thoughts on this? Is a Core 2 Quad worth the extra money? Is a 2.0 ghz Quad worth more to me then a Dual core 2.93 ghz? Should I forget it and wait for the i7 to become a mobile cpu?