After 11 years, PC gamers worldwide are getting the sequel to the critically-acclaimed Activision-Blizzard game “Starcraft,” a game that is widely expected to sell millions of copies in tonight’s worldwide launch.

Blizzard Entertainment, the Activision (ATVI) division known for its popular “World of Warcraft” game, is doing a rolling worldwide launch of “Starcraft 2” in all of its major markets. The game has already launched in Australia and parts of Asia, including the important market of South Korea.

“Starcraft 2,” which is a PC-based real-time military strategy game, is expected to be one of this year’s biggest-selling video game titles even when compared to the much-larger console video game market.

Analyst Mike Hickey with Janco Partners estimates that Starcraft 2 will sell 7 million units during Activision’s 2010 calendar year, exceeded only by Activision's “Call of Duty: Black Ops.”

Estimating a profit margin of 45% on the $60 game, Hickey expects “Starcraft” to bring in $145 million in net profits for Activision on $350 million in sales.

Wedbush’s Michael Pachter expects “Starcraft 2” will sell 3 million units in the first week, 5 million by the end of Activision’s quarter ending Sept. 30 and 7 million by the end of the year. With discounted pricing in South Korea, Pachter expects “Starcraft 2” will bring in $100 million in operating profit for Activision this quarter.

Here in the U.S., pre-orders for “Starcraft 2” are estimated to be in the 800,000 range according the industry tracking site VGChartz.com. The game has also remained at the top Amazon.com's best-selling video game list for 121 days.

The original “Starcraft,” released in 1998, has been named repeatedly as one of the best PC games ever made, eventually selling 11 million copies since launch. In South Korea, the game is nearly a cultural phenomenon where professional players compete in televised competitions watched by millions. The country also has two cable channels dedicated exclusively to the game.

Unlike the original “Starcraft,” Blizzard decided to split the game into three parts. The other two expansions, which do not have release dates as of yet, are also expected to bring in millions of sales when they are released.

Shares of Activision Blizzard were up 2% on Monday at $11.98 per share.