By gridoo (1,737-1·22) on 2009/05/11 (Patch 3.1.1) Report
If you are working on rep like Exodar and you want to keep earning rep after collecting 25 Valiant's Seals, don't hand in "The Valiant's Charge" quest until you are exalted and save them to instantly complete "The Valiant's Charge" quest on faction that you are already exalted with.
I think gridoo's comment is well worth repeating.
Once you have become become a Champion of all of your faction's races, regardless of your reputation with them, you will lose the ability to do any of these dailies.
You will be left with basically only three ways to increase your rep:
1) Buy the tabard and run instances.
2) Go back and try to figure out where you left the beginning guest chains, and pick them up again. In many cases, you will have to do a whole bunch of prerequisite quests before you can actually do the one quest in the chain that gains you significant rep.
3) Do the 4 dailies where you can choose a "Champion's Writ" (good for 250 rep points each). Raising rep with "Champion's Writs" takes forever and 3 days.
If you are not at exalted rep with a race by the time you have your 25 Valiant's Seals, just hang onto them and keep doing the dailies until you are. Then move on to another city and repeat.
You will not be able to do the big Argent Crusade dailies (given by the three NPCs in the middle of the Argent Crusade tent until you are exalted by all of your factions races.