Lifehacker kind of looks nicer only loading reloading the story and not the whole page. I gives things an application feel rather than a collection of pages and saves a heap of extra processing, why run the code again to generate a header and footer and side bars constantly when the version the user is seeing is perfectly up to date.
The experience is slicker - if you run a search on lifeHacker, you can click through and browse the results without affecting the rest of the page (including the list of results). With traditional page refreshes this would not be possible.
