Blizzard Entertainment is under pressure to deliver something big before the end of the year, now that it has delayed Diablo 3 until 2012. It has plenty of options, but signs point to the company finally dropping details about its hotly-anticipated next online game, code-named “Titan.”

Blizzard is the developer behind World of Warcraft and it’s currently the dominant force in online. Its largest gaming event, Blizzcon, is coming up in Anaheim, Calif., in October, and is likely to be the site of major news announcements. That’s because Blizzard is now facing pressure from Electronic Arts, which threw down the gauntlet by announcing it would release its highly-anticipated online game Star Wars: The Old Republic in December this year.

“If they are holding any juicy details, it’s going to be announced at Blizzcon,” M2 Research senior analyst Billy Pidgeon told VentureBeat. “The big news is probably going to be a Diablo 3 date and a possible new announcement about one or more new properties.”

Titan will likely succeed — and possibly kill — the company’s most successful online game, World of Warcraft. That game is the last of a dying breed, a subscription-based online game with more than 11 million users that pay $15 each month to access the game.

Blizzard Entertainment announced World of Warcraft in September 2001. It came out in November 2004 after being in development for more than three years and after several delays. The game was immediately a hit with fans of massively multiplayer online role-playing games — or MMORPGs — and ended up killing several other subscription-based online games, such as Tabula Rasa and Star Wars: Galaxies. The game grew like wildfire, eventually reaching a peak of more than 12 million active subscribers.

But World of Warcraft is hemorrhaging subscribers, falling to 11.4 million active subscribers in the first quarter this year and then 11.1 million subscribers in the second quarter. Free-to-play and casual games like those developed by Zynga have emerged as a significant competitor to more traditional online games like World of Warcraft. Blizzard tried to counter its losses with its own free-to-play version of the game. New World of Warcraft players can run through the game’s first 20 levels without paying a dime, but have to start paying the subscription fee to go past that.

“It’s normal to see some declines,” Blizzard Entertainment chief executive Mike Morhaime said. “We have seen an increase in new account creations (thanks to a free trial version), but it’s still too early to tell on conversions to subscribership.”

In the past, World of Warcraft has successfully taken down a lot of other online games. But it hasn’t faced competition in the MMORPG space from a major video game company like Electronic Arts, THQ Interactive or Take Two. Until now, none of these have tried to show down against World of Warcraft.

That will change come December 20 this year, when Electronic Arts releases Star Wars: The Old Republic. BioWare, the team behind smash hits Mass Effect and Dragon Age, is working on this online game, which has been in development for several years. It’s a spiritual successor to the Knights of the Old Republic series, which was very popular with gamers on the original Xbox console. Electronic Arts is betting on the team, which consists of some of the best developers in the industry, delivering another hit capable of bringing down World of Warcraft.

Electronic Arts has timed its release perfectly, because most gamers will be on vacation or heading home from college to spend time with their families during the holidays. That puts some pressure on Blizzard to respond, if only to keep the buzz about its own games simmering.

Academy of Interactive Arts & Sciences board member Zack Karlsson doesn’t think Blizzard will announce Titan at Blizzcon. However, he told VentureBeat, Blizzard might want to move aggressively to counter the launch of The Old Republic.

“If I’m them, I park it right on top of some big (The Old Republic) announcement,” Karlsson said. “I’d want (The Old Republic) to spend something big, drop some cash, and then run right over them and trump marketing dollars with PR.”

Announcing Titan is not the same as shipping it, however, since Titan won’t be on the market for some time. That means Blizzard will be fighting EA’s shipping game with vaporware of its own.

A leaked product schedule that hit the net in December last year (below) indicates that Blizzard could release Titan in the fourth quarter of 2013. So far the schedule has been accurate (outside of Diablo 3’s delay). Financial research firm Wedbush Securities analyst Michael Pachter told VentureBeat Titan news probably wouldn’t see the light of day given that it’s a 2013 release.

Blizzard, after all, is known for releasing games when they are ready — not when a release schedule dictates it. But the schedule would give Titan a roughly three-year lead time for the game, which is similar to the lead time for World of Warcraft, Starcraft 2: Wings of Liberty (announced May 2007 and released July 2010) and Diablo 3 (announced June 2008 and originally slated for late 2011).

“We commonly use the term ‘soon’ when referring to Blizzard releases, because we know that no matter how hard we’re working to reach a target, we’re not going to compromise and launch a game before it’s ready,” Blizzard CEO Morhaime said.