If memory serves correct, F.F. Bruce has an excellent book that touches on this topic some called "The Canon of Scripture." Besides some theological reasons as not including the intertestamental books into the Canon of Scripture, it is my understanding that the primary reason those books were not included in the protestant Canon is because those books were Greek writings, and never considered by Jews as part of the Hebrew Bible. Thus, while recognizing the importance and value of those books, since they were not even regarded by the Jews as canon, the protestants went along with the Jews in that regard. But even with that said, those books were by no means of little influence with the Jews. Indeed, the Jewish holiday of Hanukkah (the festival of lights) is based entirely upon the story of the Maccabees, and the Jewish revolt, as recorded within 1 & 2 Macc. This was a festival, that while not prescribed within the law of Moses, was even practiced by Jesus, as recorded in the gospel of John. If I'm not mistaken, Jews regularly read that story at that time, even though they do not regard those books as part of the canon. I guess one could say they venerate it like many Christians venerate Foxe's Book of Martyrs. An inspiring read, and of edifying value. But, it's not something you want to include in Canon :-)
Thank you all for the responses from what I have understood, if you can push past some of the boring stuff the Apocrypha is an edify read but should not be regarded as the Infallible Word of God as the actual Books of the Bible are.
Here is a PDF link to part of the book Jimmy mentioned; FF Bruce, The Canon of Scripture.http://www.holyfear.net/pdf/bruce/canon_bruce.pdf