By Pentadact

The ongoing story here is that Valve pronounced their expected batch of unlockable weapons for the Heavy would also include an unexpected fan-made map, cp_steel, a brand new Payload map, Badwater Basin, a whole new game mode, still unnamed, and five new maps ‘arenas’ for that mode.

They’re revealing these elements day by day until the whole thing goes live on Tuesday (probably around 8pm BST, I’d guess). The latest is that the replacement minigun, Natascha, slows enemies ‘for an instant’ when they’re hit. But the real news is the image of the thing: not the gun itself, but that the blurred scenery the Heavy is standing in is green grass and grey rocks: a type of terrain so far unseen in any TF2 map.

Mess of original post and updates follows:

Sandwiches: While the names might be enigmatic and the descriptions missing, if you download the icon set for the Heavy achievements Valve have just revealed, the filenames are more explicit about what they’re for. The interesting ones, name then filename:

Konspicuous Konsumption - Eat Sandwiches
To regain health, one assumes. Something Awful hint was “Think PopEye”.

Sypalectical Materialism - Uncover Spies
Combined with the Something Awful hint “Think Ghostbusters” I wouldn’t be surprised if they did a Medigun that did nothing except turn red when used on a Spy. Also, I once said to Robin Walker and Erik Johnson, “You guys should make a Medigun that lights up when it’s used on a Spy” and they said “That’s a good idea”. Then I saw them take notes, then scurry off to their PCs, and make that, and put it in the Heavy update.

More probably, as several commenters say, it’s just an achievement for hitting Spies while they’re cloaked, and nothing to do with seeing through disguises.

And not for nothing, but that Spy has a giant freaking silencer.

0wn The Means Of Production - Clear Stickybombs
The interesting thing here is the icon - that’s not a Sticky being pushed back slightly, it’s breaking. Not also the zero in ‘own’, to emphasise how totally pwnsome the means by which you do this is.

Five Second Plan - Teleport Fast Kill
This is probably just for killing people shortly after you come out of a teleporter, but there could be more to it.

Update! Craig points out that this compilation of the SomethingAwful hints is now two-for-two. The third unlock, according to this, is a minigun that slows people down. If true, a) I will be surprised, b) there will be riots, and c) ha! In your face people who said the Hobbler could never be done because slowing people down is always a bad idea! I may entirely agree with your claim and not even really like my own idea, but if Valve do it it’s automatically right.

Day Two! Click the image for details, and the names of all the achievements. Some of them strongly hint at what the other unlocks might be. Others - Pushkin the Cart, Stalin the Cart and Permanent Revolution - are just genius.

TF2 blog has the official word, the Heavy update site is detailing the changes day by day, and it all goes live one week from today. Holy, holy shit.

Five of the new maps are for the new game mode, all of which is currently mysterious. The sixth new map is a new Payload one focusing on wide-open spaces, and the smart money is on this being the oft-mentioned one where the cart is a platform you can build Sentries on. The seventh is an officialised version of cp_steel, that incredibly awesome-sounding changing map Chris blogged about ages ago and for which I’ve never been able to find a good server running.

Worth mentioning: some goons at Something Awful claimed to have playtested the update and offered enigmatic hints as to its content a while back. One of the three said, against all odds, that the Heavy update would come with a new game mode.

Another says “think Popeye”, but also claims the update will cost money, which is patently false.

The third says “think ghostbusters… it’s really that weird.”

Edit: Seven! Seven new maps! Maths degree, right here!