We've resurrected an old thread, but it's relevant. I've been thinking about this a lot lately, too. There are several references to "new heavens and new earth" and the "re-creation" and "I am making all things new".
Isaiah 65:17 has the first reference to "new heavens and new earth." Here, God says: "Look! I am creating..." The Hebrew word for "creating" is the same work used in Genesis regarding when God created the earth. This seems to me to be a physical creation.
The idea I've been toying with is: what if this really was a NEW heavens, that is a completely new universe, or a new extension of ours? And what if this really was a NEW earth? Why would Revelation 21:1,2 have anything to do with the CURRENT earth if God was making a new one? A fascinating thought to me.
If you've seen the moving "Knowing" with Nicolas Cage, that's something that was explored a little. You realize it at the end of the movie. Not the best movie there is, but definitely an interesting twist on the end of days and this new earth concept.