It is useful, when talking about the Jewish messiah (little “m”), to set aside all of your notions on Messiahhood learned from Christianity or Jesus, or for that matter, Sun Myung Moon or any other person claiming to be the Messiah (big “M”).
Wikipedia article on the Jewish messiah:
http://en.wikipedia.org/wiki/Jewish_Messiah
Here’s what I was taught, back when I practiced Judaism. The Jewish messiah, the moshiach, will be a super-king of Jews (a King-zord if you will). He will unite the Jews and ensure that righteousness prevails throughout them. When this is accomplished, he will be the instigator for collecting all Jews in Israel and rebuilding the Temple.
Throughout history, many people have been held up or claimed themselves as the moshiach. Many of these (most famously Shabbetai Zvi) were forced into apostasy. Some (like Bar Kochba) just plain old died. Thus, they failed the final criterion, the rebuilding the Temple thingy. So, many Jews continue waiting.
In Reform and Reconstructionalist Judaism, though, they have gotten sick of waiting. With, as I understand, with the rise of Zionism, they have started to excise any mention of the messiah from the prayers. Where the very Orthodox Lubavitchers (many of whom claimed their Rebbe Schneerson as a moshiach) sing “We want moshiach now, we want moshiach now, we don’t want to wait”, the Reform and Reconstructionalist crowd see the establishment of the State of Israel (presumably with a capitol in Jerusalem) as a sort of fulfillment or something that has made the moshiach irrelevant.
The question of abortion in Judaism, as I understand it. Even for very religious people, life does not start before 40 days gestation. Before 40 days gestation, there is no questions about abortion, although presumably elective abortion is frowned upon because of God’s commandment to be fruitful and multiply. I believe that after 40 days, the life of the mother always takes precedence as, I guess, saving the mother gives you a chance to make more babies rather than stake everything on just that one.
The question about the moshiach and abortion is a question that makes no sense from a Jewish standpoint. Judaism is much more focused around study and righteousness leading a person on a path towards becoming a moshiach. While I’m sure there is eschatology about people fated to become the moshiach (the red heifer thing, IIRC), the fact is that any old person can walk in off the street, study hard, become a Jew, and perhaps then go on to lead the nation, round up all the Jews, inspire righteousness, and rebuild a temple.