Here's a roundup of Pesach and Haggadah-themed posts at the Seforim Blog.
I. Racy Title Pages Update II 12.01.2005.
Discusses the title page of the Prague Haggadah of 1526. This particular Haggadah used an illustration of a nude woman in the Haggadah's quotation of Ezekiel 16:7 ("I cause you to increase, even as the growth of the field. And you did increase and grow up, and you became beautiful: you breasts grew, and your hair has grown; yet you were naked and bare"). This is contrasted with the Venice 1603 Haggadah which not only used an almost identical illustration, but even included a note alterting the reader that this is a picture of a man!
II. Eliyahu Drinking from the Cup 3.29.2006.
Discusses various beliefs about Elijah in connection with the Seder, illuminated from Haggadah illustrations.
III. Prague 1526 Haggadah 3.30.2006.
Discusses this first fully illustrated Haggadah. Since according to rabbinic tradition Abraham was called an Ivri because he came from "the other side" of the river, he is depicted in a row boat. In the Mantua 160 Haggadah a similar idea is shown, only Abraham rides in a gondola!
IV. Separate Beds More on Illustrated Haggadot 4.04.2006.
Discusses the bedroom illustration in the Venice 1629 Haggadah. The Haggadah interprets "our pain" (Deut. 26:7) as referring to the separation of husbands and wives. This is illustrated with husband and wife sleeping in separate beds and a lit lamp.
V. Haggadah, First Hebrew Map, and Forgery 4.10.2006.
Discusses the Amsterdam 1695 Haggadah. This Haggadah innovated by using copper plates rather than woodcuts, making its illustrations - by the convert Abraham b"r Ya'akov mi-mishpahto shel Avraham avinu - exceptionally intricate and pleasing. Includes one of the earliest Hebrew maps of the land of Israel.
VI. Old Haggadot for Free 4.10.2006.
A notice that many important and old Haggadot are available online.
VII. Pesach Journals, Had Gadyah, Plagiarism & Bibliographical Errors 3.27.2007.
Discusses Yeshurun's special Pesach issue. The author of one of the article's method of essentially repackaging scholarly journal articles for frum Torah journals is exposed.
VIII. Haggadah and the Mingling of the Sexes 3.27.2007.
The Mantua 1560 edition of the Haggadah shows men and women working together to bake matzot. The editors even included a verse from Psalms 148:12, highlighting old and young, bachelor and virgin, seeing matzah production as a fulfillment of this verse. By contrast, in the 1609 Prague Haggadah although a similar illustration is used there is no woman working the matzah oven. The interpretation of verses appearing to sanction the mingling of young boys and girls is also discussed.
Discusses the interesting Haggadah of R. Yedidiah Thia Weil (Rav Korban Nesanel's son). Among other things of note, the author mentions that he heard that Jews have one more tooth than non-Jews.
X. Pesach Drasha of the Rokeach by Eliezer Brodt, 4.02.2007.
Discusses a newly published derasha of R. Eleazer Rokeach's Pesach , which mentions his personal Pesach customs, and of which confirms something long recorded in his name, but never known from his own words.
XI. Initial Bibliography of Important Haggadah Literature by Eliezer Brodt, 4.16.2008.
Discusses Haggadot which discuss the historical development of the Haggadah, such as R. Menachem Kasher's Haggadah Shelemah and Prof. Y. H. Yerushalmi's Haggadah and History, as well as many others.
XII. The Date of the Exodus: A Guide to the Orthodox Perplexed by Mitchell First, 4.03.2011.
Discusses possible ways of identifying the specific Pharaoh of the Torah and therefore the date of the enslavement and exodus from Egypt.
Chag kasher ve-sameach!