Considering the rarity of planets in a habitable part of a galaxy, with a magnetosphere, favorable chemistry, an atmosphere, oceans, plate tectonics, single central star, a moon that didn't fall in the roche zone and break up to form rings that bombard us, etc.. the creators of Voyager might have thought twice about giving out that map to our awesome little life supporting planet. The return message might be (as suggested in Contact) a guide to their colonization procedures.
This has been well covered - but the odds of someone finding Voyager, as compared to the approximately 30 Light Year Radius of Radio Energy we've been pumping out, is a number which pretty much approximates zero.
Actually V1 has a 20W transmitter on-board that will stay operational until around 2025. It's busy crossing into the Heliopause which means it's a transmitter far from the noise and obstructions of the solar system. The craft will fully cross into the Heliopause in around 2015 so will have a decade of transmitting in deep space.
