I went to edit my theme for the first time after upgrading, and in most of the files this is what I was greeted with:
vti_timelastmodified:TR|06 Mar 2009 02:11:16 -0000
vti_cacheddtm:TX|03 Jan 2009 02:28:24 -0000
The only code that remains normal are found in my style.css, feedburner.php, sidebar1.php and archive.php files for the theme I'm using. Everything else is that code I posted above. The blog still works, I just can't make any changes to it.
I'm hoping that WordPress comes up with some kind of fix for this...soon!!!