http://www.wow-europe.com/en/pvp/pvp-article-part2.html
Some interesting information in there.
Blizzard Europe - Battleground/Honor System Preview
Did I read somewhere that said your pvp rank would slide down if you took a vacation or something. =\It is important to note that all the PvP reward items have a rank requirement, just like normal items have a level requirement. If your PvP rank drops below the necessary rank to use the item, you'll still own it, but you won't be able to use it. However, these items will be very potent, and useful in both PvP and normal combat, although they will of course be tuned to provide the most benefit in player versus player battles. As you can see, even the lowest ranked item is of superior, or blue, quality, while the higher ranks eventually give you epic, or purple, items