"Why would they waste thier time.........."
Because it's virtually assured to be a huge financial success.
Asides from that, Blizzard can't really go in to many other directions. If they were to make a RTS it would be direct competition for the recently released WCIII. Same applies to MMOG.
It basically came down to the only other really successful genres that would be relevent to the SC universe. FPS or TPS (Third Person Shooter, and yes, I generally do distinguish them).
I won't be getting a console to play this, but I'm still going to follow it as it does look pretty interesting.
Hoping they'll be the first to pull of successfully both the "one-man army" and "small part of much larger force" aspects.
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I love the power glove. It's so bad.