(I've reworded this a bit; it looks like a number of people find this post when searching for Valor Point changes.)
Make sense? If you wanted Stormrider's Leggings now and you had 500 Valor Points and 2000 Justice Points, you're toast in 4.1. They cost 2200 Valor Points.
In 4.2, though, your 2000 Old Justice Points will combine with your 500 Old Valor Points, and you'll have 2500 New Justice Points. The Stormrider's Leggings will now only cost 2200 JPs! You're golden!
But if you spent 950 of your 2000 Justice Points on an Apple Bent-Bough during 4.1, an ilvl 346 item, you'd be toast when 4.2 drops. You'd only have 2000-950 = 1050 Old Justice Points + 500 Old Valor Points = 1550 New Justice Points. That's bad. Save your cash and get the good stuff.
So in 4.2 we'll have two new categories of currency. Valor Points v4.1 will become Justice Points v4.2. Justice Points v4.1 will be upgraded to Justice Points v4.2 too. You're going to have a lot of Justice Points v4.2, which can all be used to buy what can currently be purchased with Valor Points v4.1.
There will also be Valor Points v4.2 which can be used to buy gear that's not available in 4.1. Nobody will have any New Valor Points when 4.2 rolls out. Nobody! There's no reason to save VPs 4.1, as you'll be able to buy the same stuff with them in 4.2 as 4.1. But since you'll soon be able to spend Justice Points v4.1 on Valor Points v4.1 gear, you should save all of your Justice Points v4.1 until they appreciate in value in 4.2.
From MMO-Champion - Patch 4.2 Valor Points Rewards, Firelands Ragnaros Video, Blue Posts, Artworks
"Old epic ilvl 359/'Valor' gear is now available from the Justice Points vendor at the same prices.
'Old' rare/Justice Points gear is still for sale at the same price.
When Patch 4.2 is released, your existing Valor Points will be converted to Justice Points.
Normal versions of Bastion of Twilight, Blackwing Descent, and Throne of the Four Winds will be nerfed and will only reward Justice Points.
You can still buy the same pieces with Old (pre-4.2) Valor Points as before. It's just that in 4.2, you can buy them with JP too! It's not really that your old VPs are being nerfed so much as your JPs are getting buffed. You can keep spending your Valor Points on whatever you wanted to spend them on, as their value won't change. Just realize you'll have tons of Old Valor Point equivalents soon when your JPs get buffed.
So you should keep running heroics, knowing you're now getting 70 Old VP equivalents + 70 Old VP equivs per boss now, right?
And randomly -- Why is WoWhead.com so slow recently? We might have too many eggs in that basket. Wish someone had told me about WoWPedia earlier too. I was wondering why WoWWiki was so danged out of date.