Two musings:

- Just before the outage, DCUO was in the process of preparing to a move to "superservers". Precise information was somewhat scarce, but my guess is that they would be moving towards a single server design, akin to CO, STO, RoM, GW, etc. If this was the case, the problems with finding groups should mostly be a thing of the past, as long as DCUO can keep enough players to at least maintain one healthy server.

- WoW gives up most of it's player base advantage by having over 200 separate realms, coupled with two factions; the actual part of the player base available to group with you is to the tune of 0.25% of WoW's US (or Europe) population. To put this into perspective, a single-server, single-faction game with 10K players would have close to the same kind of player availability to form groups as WoW.
Queues, of course, are another matter due to being cross-realm.
As a matter of fact, I actually find it easier to find groups in a medium population LotRO server than I ever found in a high population WoW realm.

TO continue your comments about server types
You mention STO as a single 'superserver' model (quite correctly ofc) however this introduced HUGE problems for a worldwide mmo. I did indeed play STO (being a long term ST fan), and stuck it out until I had 2 federation and one Klingon max lvl toon.
But it was dire. The so called 'rubberband' effect killed any sort of enjoyment for me. Imagine - there I was, I cruised over a complete sector, to land on a planet I had a quest on. After 5 mins waiting for me to beam down, the game finally decided to catch up with me. I was moved at a stately pace BACKWARDS accross the whole sector. Yep I ended up after 15mins of play EXACTLY where I started from when I left the earth base. As the only european playing in my fleet, i then asked around. Finally I found another european player. To find he also had the same problems.
If I find a MMO with a 'superserver' rather than locally based servers - I for one will NOT bother with it at all.
(As an aside I felt that STO was NOT upto scratch even without the lag effects - the graphics were cheesy - and the model one where you had to pay real money for in game benefits (although most were just graphical))

Finally on topic - I am currently on a break - possibly perminent - depending on rl issues etc. Suprisingly enough, I too have played Fallout 3 (with nearly all achievements done - curse those 'get to lvl 20 as evil/balance/good' ones), I then did Oblivion (plus expansions), and im even resurrecting my Diablo 2+LOD, and warcraft3+ Frozen Throne on an old PC my work threw out and I repaired n reinstalled XP on.
What will bring me back to WOW? - Only the people (Kit, Shen, Erik n Kattie particularly - many others also). The game is to be honest, a little tired, in spite of many shakeups (or more probably Im tired of the style of the game), but the people can be gold!

@Sinthar:

What you described is more a result from bad decisions and incompetency in implementing the game, together with network issues, than a direct result of the single shard design.

Single world/shard/realm/whatever games don't need to have all servers in the same physical location. Take GW, for example; they have a single world, with different "districts" (instances of the shared world) the character can be, and servers spread out around the world, in different continents even.

Even WoW is dabbling with this kind of single shard concept. The cross-realm queue (and, more so, the cross-battlegroup queue) is an example of bridging the gap across different realms and putting the players together, which is a core capability of any instanced single-shard design. And, while I've heard some players complaining about expecting worse play experiences after cross-battlegroup queues, I didn't experience any problem, nor have I seen any believable proof of said quality degradation.