Direct Download Link (English):
http://www.microsoft.com/downloads/details.aspx?FamilyID=265e1fb5-ba97-4510-b607-2789ffdfd093&displaylang=en
This will also be rolled out automatically via Microsoft Update next week.
Update: Other languages:
German:
http://download.microsoft.com/download/7/F/8/7F85E5EB-800E-4284-AC4C-7A49FAC1315E/WebSP1_de.exe
French:
http://download.microsoft.com/download/B/1/6/B16EDAD7-983F-415E-871D-E3A33C056411/WebSP1_fr.exe
Italy:
http://download.microsoft.com/download/6/0/8/608C8631-7DC8-4B10-848F-35B19F516F5C/WebSP1_it.exe
Spanish:
http://download.microsoft.com/download/B/0/5/B05606F9-7888-4D51-A9E1-51D8020BA1EC/WebSP1_es.exe
Traditional Chinese
http://download.microsoft.com/download/4/E/2/4E2EFB9E-2FB4-47CA-B2ED-7B7BDCC59E96/WebSP1_zh-Hant.exe
Simplified Chinese:
"http://download.microsoft.com/download/2/F/B/2FB54FE1-A207-4AD2-82DB-D9FE8265F35F/WebSP1_zh-Hans.exe"
Japanese:
http://download.microsoft.com/download/3/E/F/3EFF5FF4-0E07-4F2F-84DB-384EEDC8AEEA/WebSP1_ja.exe
Korean:
"http://download.microsoft.com/download/C/4/2/C427C5B6-2CF5-402D-AC20-A5D16E8CC618/WebSP1_ko.exe"
Paul Bartholomew
Microsoft Expression Web