I often would like to reflect more than one class in the styling - such as a quantity or size (very big/big/small/etc)  and a time of year say. 

I often see this on layers using, say, colours for one class and different shaped little dots/squares/stars for the other.  Or even different sized dots for one class and different colours for the other.  Is this something others would welcome?

Can anyone think of a workround?