This "new" code Hazee mentioned is in the 2008 NEC. Only a handful of places have adopted it in it's entirety.
MANY have amendments, and the code is NOT retroactive, so don't run out and buy 50 tamper proof receptacles just because the code changed.
There is NO code regarding ground up or down!!!!!!!! Only many, many opinions.
This topic has been "discussed" dozens of times on contractor and DIY boards alike. Bring it up on a contractor board and your likely to get flamed for days.
See here for some examples:
electric ground up or down - Google Search