I have recently purchased T. Desmond Alexander's From Eden to the New Jerusalem: An Introduction to Biblical Theology (Kregel, 2008).  Originally published in the U.K. with IVP-UK, it is now available in the U.S.  Alexander has written a number of works in biblical theology, and in particular was one of the editors for IVP's New Dictionary of Biblical Theology.  His From Eden to the New Jerusalem promises to be a very helpful entry into the exciting world of biblical theology.  Alexander starts with Revelation 20-22, where John writes about a "new heaven and a new earth," the "holy city," the new Jerusalem.  There is no temple at this point (21:22), for "its temple is the Lord God the Almighty and the Lamb."  Then Alexander goes back to Genesis--the garden--and begins to unfold his own understanding of the overarching story line of the Bible.  I look forward to finishing it, and am considering using it in my Biblical Theology course at Union.  At around 200 pages it look like it might function as a perfect introduction to thinking about "whole Bible" theology.