Have we found the universe that existed before the Big Bang?

Our ability to measure cosmological distances (past 100M ly) is very limited. Past 1bn ly we are basically talking about the Hubble law, which has to be infered from other distance measurements. The Hubble law means very little as a distance estimate to individual galaxies, but can work to get an average for a good number of distant objects (within an order-of-magnitude accuracy).

More on this: http://en.wikipedia.org/wiki/Cosmic_distance_ladder

So for now, our foundations of Cosmology are still too shaky to strap a "what came before" theory on top of it.

idea for the next Dan Brown novel: scientist studies the background microwave radiation leftover from the start of the universe, and finds interesting anomalies. He soon realizes he's found a code, a message, buried in the radiation. But as he nears publication of his findings on 'God's signature,' shady forces close in around him. It seems somebody else has already deciphered the code. Coming Fall 2013: The Penrose Enigma - "I know what you did last universe"