Although Blizzard has previously stated they'd be releasing a major title this year (Starcraft II: Wings of Liberty) it appears as though we won't be seeing it for many months to come. At the very least I suppose now we have some sort of a time-frame for it.
The delay is due mostly to the new Battle.net not being ready. A developer mentioned it will "[...] take longer than expected to prepare the new Battle.net for the launch of [Wings of Liberty."] Blizzard has also stated that the new Battle.net will be an important part of all their future releases, including SC2.
The CEO of Activision, Bobby Kotick, was quoted saying the game will probably be ready "early next year." Whether this means the game will be developed and ready to enter Beta testing, or whether it means it will be done Beta testing and ready for store shelves, I don't know, but knowing Blizzard I'm willing to bet it's later rather than sooner.
Source
Starcraft Release First Half of 2010
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