Finally, after many years Microsoft released trace64 to the public, a 64-bit logviewer for the ConfigMgr and MDT log files... And yes it works in WinPE x64 too...

It's part of the MDT 2010 Healthcare package (In the Files\DeploymentShare\Applications\HTHMDT2010\Tools folder)

Download Link:
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=cd73a2c5-76c1-48b3-a366-156900bb9493

Update 2010-04-22
The link no longer works. The release of the 64-bit version of the trace utility was not approved for release so they pulled it back. It's currently a Microsoft internal tool only. When the healthcare package will be back for download, it will sadly be without the trace64 utility.