Omg, that's evil! -goes and tests it immediately-
-fails to invade anyone-
*F DkS servers.

Lol! If the patch fixes match making I'll be happy. I hope the patch doesn't screw w/ my old builds too much.
Also found this on gamefaqs, a guide to how
poise works, thought I'd help spread it around cause many of us are curious.
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CREDIT TO EWGF for post, info and testing. This is a repost! ------------
There has been a lot of talk about Poise, and adding poise, and building a loadout around it... but nobody really knew what it actually did or how it worked. I was fortunate enough to invade Toast from wikidot today, and he left me to my own devices and allowed me to test my theories on Poise... and I can provide you with some solid data. Thanks again Toast for your help and incredible patience.
1) Poise is a meter as suspected. Identical to a status build-up meter, but it regenerates much faster... it's actually much more like your stamina while blocking, except it refills pretty quick. Increasing your Poise increases the size of this meter.
2) Whenever you resist a hit-stun by being hit, you're Poise meter empties by a variable value (determined from a composite of weapon and swing).
3) When your Poise meter empties completely due to taking successive hits (or a big hit) you are prone to hit-stun for a very brief period. This period is like 1-2 seconds. Probably less then 1 second in fact.
4) Damage probably does not factor into the amount of build-up you get (as Toast could crush my poise fairly easily with a unmodified Claymore). It's by weapon-type and swing type. Weapons are rated the same if they share a type. A Bastard Sword and a Claymore can both be resisted by the same amount of Poise (aside from special R2s that vary between weapons, also, there may be some special cases). Swings are mostly rated the same... but some WDs/WRs/R2s can reduce your poise much more then a vanilla R1.
5) The properties of some swings can be altered by increasing poise. For example, Greatsword 2h R2 has a knock-back property against low poise. If you add a fair bit of poise this instead becomes a heavy stun. If you add even more poise... even this stun can be resisted.
6) I'm uncertain how long it takes a sizable Poise bar to refill from nearly empty. It looks like like 4-6ish seconds. It's pretty hard to test. A test like this is like trying to see how long your it takes your stamina to refill from empty... without emptying it 100%... while the bar is invisible.
I tested a few breakpoints to find some jazz, see what I could puzzle out. I didn't test everything... I couldn't. I didn't have the stats to wield everything, nor did I have it all on me. Adding poise also appears to be additive... not diminishing, which means you'll probably never want to stack it to high-heaven unless you're some kind of idiot.
- 40 poise seemed to stop most non-issue light stuns. Nothing that will combo you, but junk like Katanas, Barbed Swords, etc. This would probably be the minimal amount to have if you're using any larger weapons.
- 53 poise stops one 2-handed Claymore swing. Probably the most important breakpoint in the game.
- 55 stops one 2-handed Murakumo swing. Might as well go for this if you have 53. This will likely be the most common amount of Poise for sensible players that use it. Anything beyond here is cake icing.
- 76 stops one 2-handed Zwei/Gaxe swing (R1 swings only). This is probably the most you should ever go for. You'll need 106 poise to resist even 2 Claymore swings, which doesn't seem reasonable. Increasing Poise beyond 76 however will start turning certain Zwei/Gaxe (and like other) knockdowns into stuns.
Other issues.
It seems Poise may potentially suffer from the same issues as Bleed build up, aka you can damage Poise with a Phantom Hit. This is good and bad. It means that if your Poise meter empties during a Phantom Hit, you won't get stunned... however on the flip-side, you can take some Poise damage from a Phantom Hit during a roll (or what-have-you) and then have it break on a clean hit immediately afterwards that normally wouldn't have broke your Poise.