I really like your direction!
A couple of things...
I realize that the bullet points may be at the direction of the client, but I would really try to convince them away from too much information. As someone was previously stating, these billboards are passed by in a short amount of time... The script at the bottom should be plenty for means of getting attention.
The polaroids could be a little more realistic as someone also stated, I would suggest putting a light gray to white overlay (or multiply) layer to show some perspective. I also may give it a slight bevel/emboss, since polaroids can be thick enough to have the effect. I did a project for a previous employer using this effect, and I remember even going to the extent to find out the exact dimensions of a polaroid. Also there is a little raised "pocket?" below the picture, it almost looks puffed up. Here is the project I did, I wish that I had this a little bigger though to show what I mean. You may be able to tell though...
I would also have some means of contact/info, a web address would be my first choice if available so that people can find out more information. This could then offer more information like what you have detailed in your bullet points.
One last thing would be the polaroid to the right could be centered a little more on the people. Maybe enlarging the photo to show the couple better and moving to the right would accomplish this.
Hope this helps!
Edited by cclark413, 27 April 2010 - 05:17 PM.