OK, now that you have collected your 25 Valiant's Seals you can go and get and hand in The Valiant's Charge quest.
Now pick up The Valiant's Challenge which has you fighting a Champion of the Argent Crusade. Equip your lance, mount up and go speak with Squire Danny at 68.6,21.00 which is the south-western edge of the western most ring.
Again, keep up your shields, keep breaking his when he moves away then close back in. Always use thrust and you will wear him down.
Go hand in and you will get the title Champion of Storwind (or whatever race) and if you are exalted you will achieve Exalted Champion of Stormwind as well!
Now that you have another achi you can pick up the quest A Champion Rises, go back to the other tent and hand this in to get an Argent Squire pet and some Champion's Seals.
Now pick up Eadric the Pure and go hand it in to it's namesake in the corner of the tent.
Giving Away Your Money!
While your are in the area though you can pick up a daily to give 10 gold to Squire Artie and gain 100 (110 for humans) Argent Crusage rep. Anyway, back on track, go see Eadric.
Hand in Eadric the Pure and get Battle Before the Citadel (more stamping Boneguard Footmen but you have to take out the Boneguard Commander now). Next to Eadric you can also pick up Among the Champions from Luuri and Taking Battle to the Enemy (more icecrown scourge killing) from Cellian.
You can go and do these now. If you have killed the Black Knight you will also be able to pick up the daily group quest Threat From Above.
Now that you have picked up all your dailies ... WAIT ... you haven't. Go back to the other tent and you can start picking up quests for the next race to raise you level with them to champion!!
I did 2 of the valiant battles for Gnomergan after I'd finished championing Stormwind, but my bags were full so I didn't get my Valiant's Marks. So I went to work, came home and did all 3 valiants for the daily. Then I went to the mail box and I had been sent the Valiant's Marks!!
Exploit? Nah, I think if you have the quest you can defeat all 5 races and hand in 3 marks and keep the spare 2. Good to know though, you can save them up and not have to bother fighting one day!!