dioskouris, the Bible is hardly "just an astrology book," (it has a code of ethics, for one thing,) yet a lot of non-horoscopic astrology (or cultural astronomy) is embedded in it. Notably in Revelation, where the different figures easily translate into constellations. The book seems to indicate the debate between the spring equinox in Pisces vs. Aries, concluding with retaining Aries.
The reference to the fall of the King of Babylon in Isaiah 14 occurs a bit back, in verse 3. This is a common OT theme, with various metaphors used, of "pride goeth before a fall."
I just checked my Hebrew-English interlinear translation, and there is no "Lucifer" in it. Rather, the "light bringer" is probably translated as the "son of dawn," (ben sahar--gutteral h.) Both of these metaphors could easily apply to the morning star.
For a different emphasis in Is. 14:12, see:
http://en.wikipedia.org/wiki/Lucifer where the word for star might be "shining one."
Jesus in Revelation identifying himself as the morning star is interesting, given that the planet Venus is associated with love and relationships, as is the message of the NT. Venus is not all laziness and luxury, by any means.
BTW, another planet can be the morning star. Mercury is often too close to the sun to be visible, however, and the other planets would be visible and oriental to the sun much less frequently than Venus.
