According to several sources working from BlizzCon transcripts, during one of the development panels for Starcraft II one of the panelists made mention of Wacraft IV.
While discussing the unorthodox Starcraft II release plans, executive vice-president of game design for Blizzard, Rob Pardo let slip that the Warcraft IV campaigns would be released in the same episodic manner.
It's not much to go on, but this could be construed as a confirmation on Warcraft IV by Blizzard.
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Warcraft IV somewhat confirmed at BlizzCon

The big news from BlizzCon yesterday was that Starcraft II would be released as three separate titles, but an interesting piece of information was let slip during a Starcraft panel.
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June “Lyn” Park was devastated after losing to the young Spanish star Pedro "LucifroN" Moreno in the upper bracket final. Lyn vowed to get his revenge the next day and earn the BlizzCon title that he so greatly wanted, deserved. Lyn set his eyes on the Frostmourne that ReMinD was unable to secure for himself. He did just that.
StarCraft player and commentator Nick "Tasteless" Plott goes outside for a chat as BlizzCon 2008 is winding down. Tasteless gives his thoughts on the tournament as a whole, his experiences in Korea since joining GOMTV, all things StarCraft 2 and the game's influence on the future of eSports. Korean girls are pretty awesome, too.
Video replays of matches broadcast live during BlizzCon 2008 are now available online.
In a final between two legends, Ma "sAviOr" Jae Yoon defeated Lee "NaDa" Yoon Yeol 2-0 to win the BlizzCon 2008 Invitational.
The World of Warcraft global finals at BlizzCon are over. Nihilum Plasma had to take on the American team of Selective Queuers and took home $75.000 and a replica of Frostmourne.
SK Gaming's June"Lyn" Park has made good on a promise to his fans that he would win the BlizzCon 2008 Warcraft Championship, after beating Pedro "LucifroN7" Durán in two sets of matches.
Pedro "LucifroN7" Durán, the darkhorse from Spain, has unsettled his detractors and delighted his fans at BlizzCon this weekend, where he has successfully secured a seat in the finals. This 16-year old has turned into Europe's newest star overnight, tomorrow he may well go global.















D3
SC2
WC4
Interesting years to look forward to.
They can be expecting billions of $ just from releasing the 3 titles which were announced earlier (SC 2, wotlk, d3), with the expected wc4 coming somewhere nextyear or maybe beginning 2010, blizz should be looking at becoming the leadmanufacterer by far. Vivendi must be pleased with blizz ;]
Blizzard can't make a bad game. WC3 my fav. I guess WC4 will be even better. For sure!
But, it'll go out in 5 years. Could they ban tiehack&maphack in w3 ? :/
"Another female questioner asked for all the males to look as sexy as Kalecgos. While Chris Robinson said they had no immediate plans for it, they'd try to fit it in for the next expansion. He then corrected himself, adding "I'm sorry, if there is another expansion." I think by now we know there is another one."
http://www.wowinsider.com/2008/10/10/notes-from-the-blizzcon-2008-art-panel/
I think only a few of us will still be playing when WC4 comes out.
looks like blizzard is working hard at the moment... WTB all 3 titles soon as possible please :)
They don't want to talk about it, because it will ruin the release of SC2, everyone will only be looking forward to Warcraft :D.
I don't want some gay naga race and hopefully we can look forward to sexy campaigns as well!
WOOHOO Go blizzard !
hope this time ud is gonna be buffed over the other races
blizz never stops =P
nice!
D3
WC4
Blizzard will start 4 big cases in the same time?
Maybe they need more staff now.