Just to bump up an old comment on this thread that no one brought up - I think that the reason they went with 27/28 numbering is that if the ORD expansion plan gets fully built-out, there will eventually be more E-W runways towards the far south end of the airport complex, giving you parallel runways on the north and south sides of the airport. For now, "phase 2" will give you 27L/R and 28 L/R. If "phase 3" gets built out, there'll be one more E/W runway on each side, so you will get your wish of having 27L/C/R. You'll also have 28 L/C/R. The 4/22s will stay, and the 32/14s go away (eastbound planes departing on 32L usually complete their eastbound turns over my neighborhood).