[icoder]

I agree that there's quite a few leagues you will have a hard time mastering without that extra keyboard hand. However I think without that but compensated with strategic skills, you will be able to beat a range of players (plus one player campaign). Remember Starcraft ranks you among your equals, so unless you are the 'worst' player, you'll always find wins and losses balanced out to some extend.

With one hand you can still switch between mouse and keyboard for the most basic (grouping) shortcuts. Maybe there's even computer mice with some extra keys that you can configure to act like key presses.

[jon2512chua]

I play Starcraft 2 quite a bit, and can confidently say that no matter how good your strategy is, it just doesn't work without good execution against any decent player, and by decent I mean anyone above bronze league. This is because not using keyboard shortcuts slows you down by orders of magnitude, and your faster opponent can just brute force his/her way to victory.

Using MMORPG mice with all the extra hotkeys might work rather well though, but I still doubt that it's possible to get into the more serious players' leagues this way though.