From what ive heard "right sizing" the bases means right sizing the equipment in each base. Instead of having a huge 320 base in ORD, DEN, and IAD and a huge 737 base in EWR and IAH, they want to "right size" these bases. They want to spread the 737s out system wide as the 320 is. In other words, grow the old 320 bases with the 73, and grow the old 73 bases with the 320. Thats what I heard but who knows.