Here you go, from WotLK Information Wiki: WotLK Alpha Official Wiki
Official
(enUS)
http://www.worldofwarcraft.com/downl...yWoW-WotLK.exe
http://www.worldofwarcraft.com/downl...yWoW-WotLK.dmg
(enGB)
http://www.worldofwarcraft.com/downl...yWoW-WotLK.exe
http://www.worldofwarcraft.com/downl...yWoW-WotLK.dmg
(deDE)
http://www.worldofwarcraft.com/downl...yWoW-WotLK.exe
http://www.worldofwarcraft.com/downl...yWoW-WotLK.dmg
Mirrors
RapidShare: 1-Click Webhosting (PC, enUS)
RapidShare: 1-Click Webhosting (PC, enGB)
RapidShare: 1-Click Webhosting (PC, deDE)
RapidShare: 1-Click Webhosting (PC, frFR)
Torrents
WotLK-F&F-enUS (download torrent) - TPB
WotLK-F&F-enGB (download torrent) - TPB
Enjoy!