Update: Inon Zur has posted a clarification that he was in fact referring to something completely different.
There's a good chance that Fallout 4 will be announced within a few days. While there's no firm evidence that the game will be announced, it's very interesting to note that Bethesda has just, for no apparent reason, published one of the original trailers of Fallout 3 on its official YouTube channel.
The timing of the video's publication is curious given a recent statement by the composer of Fallout 3, Inon Zur, who wrote that Bethesda will be announcing a project he has been working on for some time now, come May 15. That's tomorrow!
If we consider the timing of all of this, there's a good chance that Fallout 4 may very well be that game. Hell, it's about time.
Be sure to temper your excitement, however, as Bethesda just released a statement on Twitter to game journalist Arthur Gies that the addition of the trailer was simply to coincide with the launch of the company's new YouTube channel design. "We were updating the new YouTube design and realized we didn't have it there," wrote the official account. It's anyone's guess as to why they were updating the page.
@aegies we were updating to the new youtube design & realized we didn't have it there. Updated page (in progress) youtube.com/bethesdasoftwo…
— Bethesda Softworks (@Bethblog) May 14, 2013