what does the CTS line do on the XbeeShield?

I just purchased a XbeeShield, Duemilanove, and a second Xbee/USB breakout board.

I've read all the various articles on wireless programming (Sparkfuns, Ladyadas, and another one I can't recall), none seem to address what appears to be built in reset on the Xbee shield - the CTS/DIO7 lines are connected via a transistor to the Arduino reset line.

Why is this? Doesn't this cause the Arduino to reset every time the CTS line toggles? Why can't this line be used for wireless programming instead of doing the DIO pin forwarding hack that other wirelss programming tutorials talk about?

I guess my point is that it would seem that when CTS toggles the Xbee has data ready, and it should reset the Arduino, and the program should load via the bootloader - what am I missing?