[eeperson]

You can already get pretty close to this with a Thinkpad. I have a Thinkpad T420 and it runs Debian Wheezy flawlessly. Of course you will have to make some tradeoffs in the weight/battery life department because Linux isn't as good about battery life. However, I am able to get about 5hrs with an extended battery and it still feels lighter than a 13in Macbook Pro. You can also replace the CD/DVD drive with an extra battery if you want longer battery life without affecting weight much.

[kamechan]

i have a t420 running arch, and am able to get 13 hours on idle and 10-12 doing work. posted something about how i did this here: http://news.ycombinator.com/item?id=3564400

[eeperson]

Thanks for the tip. I always wondered what kind of battery life I could get if I tweaked things.