OLPC XO OS build 703 has at least two significant changes:
The first is that it automatically suspend when closed, with this caveat:
the system can’t suspend when the USB bus is in use by an external device (unless it’s a USB mass storage device and has been fully allowed to write any cached info and quiesce itself).
This might not seem like a big deal, but folks have been wanting it for a long time.
The second is that activities no longer come pre-installed in the OS image.