The vision John has is not of people leaving earth and going somewhere else. It's a vision of God coming here and taking up residence in our midst.
Rob Bell, sex god, p. 165
The context of the quote above has to do with Revelation, more specifically the end, where John tells us of the new heaven and new earth, and the new Jerusalem coming down out of heaven.
There is really nothing new in what he's say, at least by my experiences. Granting that because death is often of more immediacy then the second coming, or at least of more apparent immediacy, among the churches I've been to the question of a person's destination after death has usually been of more immediate concern than the coming of the new Jerusalem; still, it did get it's share of teaching about and mention.
And one need not go even to Revelation to see it. Zechariah in the OT tells us of a time when Christ will return, and for a time make things right here on earth.
My problem with Bell here, and emergents as a whole, is a small one, at least in comparison with some other things they say and teach. It's small and subtle, but I think of at least some small importance.
It has to do with his claim of God "coming here", with the inference, or so it seems to me, that it will be to this earth that the new Jerusalem will come.
This seems to miss the idea, both in Revelation and elsewhere, that things are they are now are not meant to last forever--that the earth is kept for a time of judgment, that as it is now will someday be destroyed, and perhaps the whole of the university as we know it along with it.
As the passage in Revelation says, John saw a "new heaven and a new earth", because "the old heaven and earth had passed away". In something that to me seems very similar to what happens with us in regards to the resurrected body, the material world will also "pass away" and either be replaced with the new or be itself made new.
Although perhaps a small thing, like I said before I think it is of some importance. More than one place in the Bible tells us to hold lightly onto things of this world, and to look for the next--"Do not lay up treasures here on earth...but lay them up in heaven", "Our citizenship is in Heaven", "Love not the world, nor the things of the world".
One big problem that I think emergent has is in their emphasis on this world. True, few if any of them come out and say that there is no Heaven (though Pagitt's harping on dualism comes close), but it seems to be an embarrassing topic to them. In watching at least one online video of McLaren, it seemed that he wanted to drop the subject as quickly as he could, so he could get back to the issues he thought of more importance. Given the McLaren has pretty much adopted a full-preterist outlook in regards to prophecy and Christ's return, which is that all biblical prophesy has been fulfilled including those about Christ's second coming, then his focus on this world is really all he has.
If this world is all there is, then "laying up treasure in heaven" becomes an act of futility. If this present world is the "new heaven and new earth", I have a great desire to demand a refund, because it most certainly had to have been a bait-and-switch, because the reality would be far less than what was advertised.
Saying this world is temporary does not make it unimportant, any more than saying that our present life is temporary makes it meaningless. If anything, knowing there is something more waiting and coming, something new, and that some of our actions, small as they may be, can influence our individual place or lack in the new heaven and earth, makes this life of no small importance.
And if anything, the teaching that "this world is not our home" should give us heart to do right when faced with dangers and even death. Especially since the teaching is true.