This is an editorial by Lilgreenman which analyses the recent development of the “We Want Half-Life 3” fan campaign from a retrospective standpoint. All views expressed in this article are his own.
Articles related to Source 2 ?
Community Spotlight: Half-Life 3: Awaiting Assignment

Whilst many of us have been waiting very patiently (or not so patiently) for news on the next Half-Life sequel, web designer Tom Bennet has been busy putting together a rather stunningly designed retrospective in celebration of Half-Life 2’s 10th anniversary.
Source 2 and New Source Tools Casually Released with Dota 2 Update

Recently Valve introduced new tools for the Dota 2 Workshop. But these are no meager ‘Authoring Tools’, this a full blown, updated, next gen, set of tools. Complete with a new version of Hammer, a Material Editor, and a Model Editor.
Gabe Newell’s AMA Round-up!

A while back Gabe Newell stated that if The Heart of Racing charity reached $500,000+ in donations, he’d host an AMA session on Reddit. And a few days ago, they passed said stretch goal, and Gabe went on to announce that an AMA would be held on March 3rd at 1:00 PM PST.
17,000 users visited the IAmA subreddit, waiting for Gabe Newell to start the show. And they waited for a while, but nothing happened. Well, at least not for another 25 hours – then it started. Valve time, ladies and gentlemen.
Nevertheless, it happened. Erik Wolpaw, Erik Johnson, Ido Magal, Greg Coomer and Gabe Newell all sat down to answer the question that the fans might have. Let’s take a look at some of the more interesting answers we got.
So who wants to see what Source 2 looks like?

You ever notice how just as the community starts to drop down into the dumps, something comes completely out of left field and gives us something to talk about again? Funny how that happens with Valve…
Gabe Newell Confirms That A Next-Gen Valve Game Engine Is In Development

UPDATE: In the very same interview, Gabe also revealed the fate of one of Valve’s most secretive game projects. Check it out, right here!
Earlier this summer, we found traces of code within the Source Filmmaker that clearly indicated Valve is actively working on “Source 2“, a next-gen game engine built on Source’s foundation. While the news made quite a stir all throughout the Valve community, it didn’t have the same effect it would have had, if Valve had officially confirmed Source 2’s existence.
Well, some months later, it appears we finally have been given just that. Read on!
Oh My God, Source 2 Is Actually Real – And A Sneak Peek At The New Hammer Editor?

UPDATE 3: Facepunch member J*Rod has created an insightful and very informative explanation of how Source 2 might work, based on what we’ve seen in the leaked code. If you can’t read code (or as I like to call it, hieroglyphs), then this is your lucky day.
UPDATE 2: LambdaGen fan 3rrorVirus has made this hilarious little video about this whole Source 2 debacle – check it out!
UPDATE: Facepunch member DevinWatson has compiled a full list of just about every single Source 2 reference in the SFM files. Take a look!
Yeah, it gets better. Waaay better.