I have the lorekeeper of pandaria achievement now and have from what I can tell, unlocked every faction, I read that to unlock the dailys for the "Shado-Pan" and also "The August Celestials" you are required to be Revered with the "Golden Lotus".
Just from questing and about a day of dailys since hitting 90 as a human, I have managed to get my current faction standings with the main factions to;
Golden Lotus - Neutral, 2550/3000
Order of the Cloud Serpent - Honored, 3000/12000
Shado-Pan - Friendly, 5586/6000
The August Celestials - Neutral, 1200/3000
The Klaxxi - Honored, 5652/12000
This entitles me to 7 daily quests from "Golden Lotus" which gives about 200-ish rep and once friendly you unlock 20 more so after tomorrow I will be gaining about 5400 rep per day, friendly to honored is 6000 so it would take 2 days after todays reset to get to honored then you unlock 15 more at honored, so would then be gaining 8400 per day if you did all 42 quests, honored to revered is 12000 so would take 2 additional days of doing them all to get revered and that then unlocks the ability to do daily quests for "Shado-Pan" and "The August Celestials" and roughly another 3 days to get to exalted so 10 days in total.
Once unlocked the Shado-Pan offer 5 daily quests at 3 differant hubs with each giving 250 rep except the last one which gives 350, so 1 day is essentially 4050, so to get my rep from where it is now it would take 1 day to honored, 3 days to revered and about 6 to get to exalted, so totalling at around 10 days this being 10 days after I already took 10 to do the "Golden Lotus" obviously at this point "The August Celestials" can be done alongside the Shado-Pan quests so not going to attempt working that out too.
My point though, blizzard did say before they didnt like the fact people "Need" to log in to do dailys or a specific dungeon or whatever as more of a chore then anything else, yet now it is a case of if you dont do the dailys every day you wont get the rep or it will become a much longer process. Now I understand not everyone is going to be that bothered about getting the reputation rewards anyway but also the fact that to spend justice points now I am required to have honored standings with the factions, so I would "Need" to log in and go do the dailys for "Golden Lotus" to even unlock the other two and then have to do those aswell to get honored standing to purchase the items with justice points, personally I havent seen if there is going to be a new justice point vendor added at a later date that requires no rep just sells the gear, but as someone that is farming heroics to gear up now in 20 days worth of gameplay I very much doubt that I would need the items those rep quatermasters are selling anyway but also the fact that I only have 1 faction currently that I can spend justice points with, for a chestpiece that has already been replaced.
It just seems like a cheap way of making players have to come online every day and I would like to hear other opinions about it, I dont know why they decided against the use of tabards to gain rep as we have previously seen, but it wouldnt be so bad if I could atleast spend my justice points because over 20 days worth of daily quests I'm pretty sure I can amount way more then 4000 justice points.
(If I have missed reading that they are infact adding another justice vendor at a later date thats great and I look a fool but still this seems like a very long winded way of getting people to play the game rather then giving us the dailys as an option to gain rep faster and use the tabard otherwise)
P.s apologies for long post it is also my first, I am no longer in a guild and have people to moan to about it and get responses in regards to it, also the math is no way going to be 100% because math is the worst.