I also think that tabs should default to 4 spaces long (in length, not expanded), but that is just me.
I like 4 spaces, too. But consistent indenting, properly applied, is more important than the amount of indenting actually used.
Considering the fact that the IDE is designed for much smaller monitors than are currently used today, 4 spaces will indent code off the right edge of the screen very quickly.
So, when making this change (as if I believe it will ever happen), the size of the monitor should be looked at when sizing the window. The user changed size of the window should be recorded and reused, too.