How is running over to Cain to ask him to ID your things not a "meaningless gesture treating us like children" if the current system is? Or having to pop a scroll and ID the item? It's simply a different system and one that doesn't take up inventory space. Speaking of fearing change...
As to the OP:
I've played a fair amount of "That other game." The currency system is.. awkward. I love the idea of the crafting/item orbs, but using them as currency for vendors is really awkward and feels forced in its execution, as if they had the idea of creating a barter system with the NPCs to emphasize the destruction of a civilized world but stuck with it even though it didn't work as cool as the system seemed on paper. The worst part about the system was how much of the inventory was dedicated to currency items.
I make some assumptions that people understand some basics: D1 and D2 gold was broke. Identification and Town Portals systems were broke. But they all could be improved by Blizzard.
RE: "As to the OP" Just because the other game's system is currently awkward in beta doesn't mean the entire system is permanently broke or could never be improved. Shards in bags. Orbs accessible from shared storage. Already covered (fixed") in Diablo 3.
You assumed that I think the D1 and D2 systems including Cain were great. "Fearing change"? As my other post reflects, I said that I expected Blizzard to improve on the systems. D1 and then D2 gold, portals, and identification was just broke. I kind of expected that everybody knew that by now.
Yet you insult the D3 system without really much reason behind insulting it. The comment that the current system is a meaningless gesture made absolutely no sense. They've explained why they want people to identify things -- because of that Christmas present feeling -- but they also have made it pretty obvious they don't want inventory space cluttered with non-essential (that is non-gear) items. Even crafting mats have been reduced fairly significantly by removing the white components. This isn't a game in which bag packing is the main concern (as can be seen by the developers' decisions).
I fail to see how your proposed system will fix the gold and scroll systems from D2 any better than D3. I think, honestly, they'll break the system even more than D2's.
As to the issues with PoE's systems - it really isn't the inventory issues that make the system feel awkward. It is a cool concept on paper to simulate bartering, but bartering with NPC's just becomes awkward. The key for bartering is the back and forth as each party determines the value of what they want and are willing to give in non-currency terms. PoE's system was just clunky when I played with it (I played before they implemented selling gear and tried that system once for a while it was implemented, as well). It felt like it was the developers forcing a system onto the community when a non-gold currency is almost always something the community itself determines. It's like if Diablo 2 had Stones of Jordan forced as the currency of the game instead of it happening because the community's trends. PoE's NPCs working with the orbs and currency items felt like they were trying to hard to get the idea to work, as if they decided early in the development process that they didn't want gold and had a very hard time getting a system in which it worked. To me, it helps highlight why it's such a good thing that the D3 development team is so willing to sacrifice the golden calf, as it were, for their game -- from runes as items to a flat Inferno -- for the sake of the quality of the game and how it plays. An idea can be a great idea but if it doesn't play well, it probably shouldn't be in the game.
True, the PoE system theoretically can encourage people valuating different currency items for different amounts, which can theoretically be compelling and make for intriguing trade scenarios, but it most likely will come down to a forum-based evaluation. A specific unique item, or good rare, will be worth so many of a certain orb, and each orb will have a community-established value compared to each other orb. It really will just get awkward to have to go through the markets and forums to find the values of things (which will almost certainly be established even if the intended goal is to let them be on a person-by-person basis).
Don't get me wrong, I understand how broken gold was in D2, but I don't see why simply making gold worth something in D3 isn't a good fix. Civilizations develop currency for a reason -- it makes commerce function much more easily. It's the one time having that middle man of money is actually more useful. A money-based currency is easier to deal with because it is consistent and easy to communicate a value among many different parties. A non-gold based system would probably work fine if the currency that replaced it was one or two items at most that had a clear and distinct conversation rate. I would say that if PoE wanted to keep their system, they should stick to only one or two orbs (or just their scrolls) being currency rather than the whole slew of them.
In response to the OP's tl;dr -- the "value" of identifying things doesn't necessarily affect the value of unidentified things, which get their value not from the cost of identifying it but from their potential. The reason an unidentified rare may have more demand than a specific identified one is because it has the chance to be a perfect rare, and the cost of identifying an item is only a very marginal effect on item values. Interestingly, there seems to be demand both for random/uncertain results and for specific/certain results in other games. For example, in Magic the Gathering, there is demand for boosters (which provide totally uncertain and unlikely prospects for a specific rare card) and for those specific cards people are seeking.