BizTalk Server 2004 Service Pack 2 is now released to web. All BizTalk Server 2004 customers are encouraged to read the release notes carefully and install the service pack as soon as possible.
English:http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=en
Chinese (Simplified):http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=zh-cn
Chinese (Traditional):http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=zh-tw
French:http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=fr
German:http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=de
Italian:http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=it
Japanese:http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=ja
Korean:http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=ko
Spanish:http://www.microsoft.com/downloads/details.aspx?FamilyId=D20B4510-E5A6-4D7B-87A1-4BD52BDD57B8&displaylang=es
A fix list can be found here: http://support.microsoft.com/kb/924330/en-us