Also, if you haven’t already seen it Menachem Mendal has a very interesting post about using oat matzo for pessach. He also has a great post on another story assumed to be of Jewish origin which is not (the story of the two brothers and the temple mount).
Also one hopes that Mississippi Fred McDowell will post on his excellent site English Hebraica, on the early haggadas printed with English or in England.
Finally, although not directly related to pesach, although it would not be that hard to tie it in, there is a new Mishna Berura Yomi blog for all those wishing to devel deeper into this work.