As hinted at yesterday, Valve Software have today revealed what famed DOTA developer Icefrog has been working on for them over the past year: DOTA 2, proclaimed as "a massive sequel for one of the most played games in the world".

Dota 2 promises to take the unique blend of online RTS and RPG action that has made Dota popular with tens of millions of gamers and expand upon it in every way.

Unfortunately, they've annoyingly left all other details out of the press release to promote an exclusive article at gameinformer, who's site is currently unable to cope with the increased traffic.

Hopefully this is yet another lesson learnt on why exclusivity in online PR material is a stupid idea, but until the smoke clears, you can read the article via google cache.

Here's an excerpt:

Valve's approach to Dota 2 is unusual in that the gameplay itself is remaining almost entirely untouched. "Our first reaction is to assume that [design elements are] there for a reason," project lead Erik Johnson explains. "IceFrog is one of the smartest designers we've ever met. He's made so many good decisions over the years in building the product. He virtually never makes a decision that doesn't have some reasoning behind it and a way to pick apart the logic behind it." This approach means that Dota 2 basically is DotA-Allstars with new technology.

DotA-Allstars' roster of 100+ heroes is being brought over in its entirety. The single map games take place on is functionally identical to the one that you can download for free today in the Warcraft III mod. Items, skills, and upgrade paths are unchanged. Some hero skills work slightly better due to being freed from the now-ancient Warcraft III engine, but Dota 2 will be instantly familiar to any DotA player.

A few things will make significant differences to players making the transition. Dota 2 uses Valve's Source engine, so the game is much prettier. Source itself is getting a few upgrades, including improved global lighting and true cloth simulation. Dota 2's integrated voice chat is a huge step up from having to set up your own Ventrilo server, and the speed of voice communication is very nearly a requirement for a game as team-focused as DotA.

Other significant points include AI taking over for dropped players, the cartoony visual style of WarCraft 3 is to be retained and Steamworks integration will be getting even heavier with rewards even for things like posting in forums and providing feedback.

The article also touches on the hostile nature of communities in the genre and describes how Valve are attempting to address that:

Finally, a coaching system is being deeply integrated into the game. By logging in as a coach, veteran players can do their part to help out newer folks. Valve hasn't entirely decided on the specifics of how newbies and coaches will be matched up, but once they're together a few things happen. The coach sees the pupil's screen, and gets private voice and chat channels to communicate with them. The coach probably won't be able to take control of anything directly (once again, the details are currently under discussion), but information is power in Dota 2 and having a mentor whispering in your ear can make all the difference in the world.

A noble pursuit to be sure but we'll have to wait and see whether it will be enough to sooth such a savage beast.

No in-game media have yet been released but the character art indicates that despite being creations of Blizzard's Warcraft 3, many of the game's heroes will retain their general appearance in the sequel - how they've jumped that particular legal hurdle remains a mystery.

DOTA 2 is due on PC and Mac in 2011.