The last week I started to gather Marks of Honor for Burning Crusade. Since You will be able to purchase Items for honor with the new system I figrued it could not really be wrong to start gathering them to turn them in when honor is no more useless.
Then I also stumbled over this screenshot:
Apparently You can also turn in token to receive your epic mount. At the current price it may not been that great (8g for Alterac Mount) but if you look at the other screenshot it seems that you can ride this epic at 55 now with riding skill of 75. So you basically save the expensive riding skill.
Edit: They changed the mounts to 150 riding required.