I grew up loving heaven. The best part of the entire Narnia series was when the children ended up in Aslan's country and never had to leave. Whenever I thought about angels and glorious spiritual realities beyond my ken I would have this sense in my physical body of buzzing and tingling that I only later associated with the presence of the Holy Spirit. Everything "heaven" was precious and wonderful. I could hardly wait to get there. I even seriously entertained thoughts of suicide on that basis, not that I would have ever carried them out. It was against the rules.
So what would cause me to question this? Try Surprised by Hope by NT Wright. If once you are aware that the primitive Christians were not at all about heaven, (If they had the response would have been "everyone knows about the after-life and everyone has a different version -- who cares about that new Jewish cult?") but rather the resurrection, you suddenly have a different end in view. We're all coming back! Heaven separated from Earth is not God's ultimate plan. We're coming back and heaven's coming with us.
So much of our theology revolves around heaven. But heaven is incomplete. Heaven is not our home. The gospel song, "I Can't Feel At Home In This World Anymore" -- I used to sing it to myself constantly -- is not actually telling us the truth. Otherwise why would the martyrs under the altar in Revelation 6 be so particular about what happens here on earth. No, the happy ending is so obviously "Now the dwelling place of God is with men!" And no, I'm not proposing some turn-of -the-last-century liberalism that says if we all work together in a non-miraculous way (who believes in miracles anymore, anyways, right?) we can bring peace on the earth and make it into heaven. But read the book of Acts and understand this statement: "With great power the apostles were testifying to the resurrection of Jesus." When was the last time when you heard someone doing that?
I think that the death that was warned of in the garden was the separation of heaven and earth. Certainly when redemption is complete, they will be one, indicating that it's a return to a possibly former, certainly intended state.
These thoughts are incomplete. I could try to rewrite the aforementioned book for you but maybe you'll want to read it yourself. There's so much here that I am constantly mulling over, just because I've never thought this way before...