Q u o t e: Blizzard said it was never "technically canceled" and it's just not a focus right now. However, nothing has been shown about the game for quite some time, and therefore many people consider it vaporware.
"Some people call it vaporware" would be an understatement. If you are still holding your breath for that game, then you would be in a small, small minority.
If we are lucky, we will see some sort of a SC:G game on the next-gen of consoles (XBox 720 anyone?), but I doubt the shape that the current game is in (which was made for last-gen, but announced for this gen) would ever pass Blizzard's high standards.