The update should be available pretty soon. But until then you can try to download webm videos from youtube. To do that:
  1. Go to www.youtube.com/html5 and enable HTML5 videos for youtube.
  2. Download the latest version of Firefox, Google Chrome or Opera, all of them support HTML5 webm videos.
  3. In Replay Media Catcher 4 go to Tools -> Settings -> HTTP Download Tweaks and add the following Content Type/File Extension
    Code:
    video/webm 
webm


    After changing settings hit the Stop recording button, then hit the Start recording button.


Many popular players support webm videos. For example, you can play them with freeware VLC player:



And you can use other popular players like Media Player Classic, Winamp, XBMC,...

Also note that webm uses MKV container, so you can try to rename webm videos to mkv to play them with your player supporting MKV. WebM uses VP8 video codec and OGG Vorbis audio codec.