Didn't we establish that Drake was Elena's father?

I don't think it's completely necessary (like the MGS series, where you HAVE to have played through the series to understand the story), but it is better if you do play the 1st. I strongly recommend you try the 1st game. It's, in my opinion, a true gem of this generation.

I wouldnt say it's vital. Only a few characters from the first seem to be making an apperance in the second and from the sounds of things it's a completely new adventure.

However personally, I would play through the first before moving on to the second. You can see the foundations of the characters made, and their relationships formed with each other, passion between Elena and Nate, friendship between Sully and Nate etc. It would be worth it for the experience alone though, Uncharted: Drakes Fortune is a fantastic game.

Damned darth spoiled that Ellena is not drake's sister for sure :(;

next monday, this game will be in my hand :)