As one of the more vocal dissenters when the change to a "Relic Based Magic Item Economy" was instituted (Basically where there was only 1 of each item), I have to say that I have not personally seem too many issues with distribution or fairness. In the games I've played in, there are generally only 2-3 people max who want any one given item and sometimes if it's a highly specialized item, there's only 1 anyways. Usually the decision comes down to:
1) Bargaining/Dealing: One characters offers some 'payment' to the others and is allowed to take the item in question OR
2) Random: Everyone rolls a die and winner takes it
#1 is a lot more fun to watch, but #2 happens a lot also. It may take a few adventures but usually these things balance out in the long run. One thing I have seen is that if someone gets an item, they don't get a share of the gold. Also if there's an item that no one wants, it's usually sold at the table and the proceeds split by those who got no magic items.
So far the authors and campaign staff have been good at item distribution in my opinion and there a few key things that have made this possible:
A) There are usually 3-5 items in each adventure now that can be given out
B) There is a nice variety in items that are being given out (weapons, armor, wands, special miscellaneous items) so that it's possible each person wants just 1 item
As long as the above continues, I don't see this as a long term problem. I've been on all sides. There have been items I've wanted and lost, items I've wanted and gotten, and times when I didn't want anything but the non-certed piece of fluff that no one else did

A few points I'd like to address that others have brought up:
Henry, you make some good points and the system does a good job of not being item-reliant. However, for the vast majority of players, *every* Arcanis game is a pick-up game since a lot of folks play at conventions or game days. Therefore, any discussion needs to take that into account.
Tony, while there may be a few characters who have enough money to retire and need nothing, I would argue that given the rising costs of runes (at higher Tiers) and the cost to buy Exceptional Weapons, that this is not the common scenario characters are in. I know personally I need to accumulate 38gp for my Exceptional Weapon and I'm about half of the way there saving up. I have bought 2 Runes in the last 4 years, so even if I'd saved everything I might *just* be able to afford it right now at Tier 2.6.
John