If you had a firm view of "heaven" in your mind - would your life be any different? This question begs another, "Just what can we know about 'heaven'?" (more on that later). Do you realize God wants what He has revealed about "heaven" to shape what it is we do in the present? Think about it, why has God revealed anything about Himself? So we change - right?
God has revealed Himself through creation (general revelation) so that people will respond by acknowledging something bigger than themselves. A response to creation ought to be something like "Wow!! This can't be an accident. I wonder what kind of God/being made all of this...does He care for little ol' me?!?".
God revealed Himself through Jesus, His Son, so that we would see, more concretely, what God's desires are. Ultimately, God desires the consummation of His Kingdom. Until that day (when Jesus returns to renew all creation) God desires the lives of changed people to impact and transform the world for His glory. A response to this revelation of God (i.e., Jesus) ought to include things like, "Jesus, save me!" "Jesus, You are my Lord!" "Jesus, I want to love people the way You love(d) people!"
God has revealed Himself through the Bible (His Word), so that we can have a record of Who God is, What God desires, and What God demands from us (this is a definition of prophecy offered by Shane J. Wood - I think it fits quite nicely for 'why the Bible' as well). When we read the Bible it is not merely to pass the time, learn something new, or make a check next to our Christian "to do" list. When we read the Bible we are to submit ourselves to It. In other words, we ought to realize Scripture is the subject and we are the object - it pokes and prods our lives...and we are to conform to it.
In light of all of this, since God has revealed so much about "heaven" - why do we do ourselves a disservice and insult God by not studying and reflecting on it more? Go ahead and read Revelation 21-22. What is the big picture here? How should concepts contained here shape us?