Help me find a proper laptop

Hello,

I am looking for 15" laptop with decent performance (Dual Core, 2GB ram, Integrated or simple power saving graphics solution).
But the most important things for me are LONG BATTERY LIFE and LOW WEIGHT.

I dont want it to be any over 2.5kg, but once again, the most important thing for me is battery life. I plan to use the new laptop mostly for business and school (email, customer support, web surfing, school (text editing, pp and more), simple video editing, iTunes, etc etc). I dont plan to do any intense tasking like movies or games.

And lastly, I want something reliable that lasts long.

Any advices?

I am open to any brand, max budget is $2,000.

Jan