I asked a couple of guys and they say that IF the louvers are at a 45 degree angle, have them face the house. In other words, you should NOT be able to see the opening(s) from the street. Wind could blow rain up into the louvers if they're facing the street. Also, when they 'face' the house, the 'view' from the street should be 'clean', meaning that you won't see 'black' as you look up.
Air is naturally drawn into the vents. Wind doesn't really give you any advantage having them facing either way.
I, too, would be interested in reading what Jason has to say too. My best to ya and hope this helps.