http://www.minecraftwiki.net/wiki/He...#Future_update

https://twitter.com/notch/status/22623080852

Notch posted on Twitter about the subject of Herobrine, early in his popularity boost.
RavenBurga Is "he" a real entity ingame or is it just a successful_troll.swf?
Notch It's not real. =) But it might be soon!


12:25 Kizzycocoa [...] is there any confirmation on his upcoming existence in MC?
12:27 Notch i have no plans of adding herobrine as is, but I do like the rumors, haha

Current stance on Herobrine

As Minecraft passed on from Notch to Jeb, the chance of Herobrine appearing in an update was unclear. On the 22nd of August, Dinnerbone, current joint developer of Minecraft, tweeted:
“ We have no plans at all to add herobrine. I doubt this will ever change. „
<small>~ Dinnerbone on Herobrine[3]</small>
This confirms that Herobrine will never see an official release in Minecraft, and that any claims of "finding" Herobrine in vanilla Minecraft in future updates are completely unfounded.