Credit:
Currently, there's no word from Google about the reasons for the outage; we have contacted Google and will update this post when we learn more.
*Update: Interestingly enough, the videos on YouTube seem to work, only the front page seems to be affected.
*Update #2: We've received the following short message from Google: "YouTube is temporarily unavailable. Our engineers are currently working to restore the site."
*Update #3: It's back. The downtime lasted approximately one hour.