This isn't what the bassist actually plays in the original song,(I think he plays a B
and a D with some fills) but this is what I like to play for the bass:

G -----------------------------------------------------------------------|
D ------10---10-9-7-------10---10-9-7-5-------5---5----------5---5-------|
A ---0-----------------0-------------------3--------8-7----3-------8-7-5-|
E -----------------------------------------------------------------------|

It's very similar to what the guitar plays, and I think it sounds good when played
alongside with the guitar. You repeat that all the way until the "Let it Rain" part. 
Then you
play an F and a C for that part, with whatever fills you want.  This is my first tab 
ever, so hopefully it is somewhat understandable :)

I have a video of myself playing this if you want to check it out and hear how it sounds 
with the song:
http://www.youtube.com/watch?v=-cBgcmFn0pE