Yes, when Apple released OSX Mavericks they made some changes to Quicktime 10 (QT 10) and tada; your camera is obsolete! (In 10.8 the WG-2 videos work fine)
The issue is that the MOV container that the WG2 creates is not quite right. If you open the file with QT7 and save it again, QT7 fixes the container and then QT10 will be able to open and play the file (so will iPhoto, QuickView, iMovie, etc.) However QT10 is unable to recognize the problem and just pukes on the file (if you try and open the file in Finder, it will tell you the file is damaged and should be moved to Trash.) I have asked Apple if they will consider making QT10 a little smarter (e.g. "this file needs to be updated/fixed, ok to make the change?"), but so far nothing. You could ask them to help us out, by giving them some constructive feedback here;
https://www.apple.com/feedback/macosx.html
If you want to manually fix all your files, you can get QT7 here;
QuickTime Player 7 for Mac OS X v10.6.3 or later
Cheers!