Low population servers are going extinct Soon™, once rollouts of Connected Realms are complete. We don't know the final "size" goal of these connected realms, but low population realms are set to be a thing of the past.
Low Pop vs. High Pop
Right now the main talked about dynamic in WoW gold making is low population vs. high population. It's inherently clear that high population servers have the possibility to make more gold than low population servers. The downside is that the gold per hour put in is lower on high pop than it is on low pop, the turnover ratio just being that much higher on a high pop that it makes it a more valuable gold making environment. There has been many a heated debate over which is better and how to compare the earnings potentials. I've personally for example have 3.5 million liquid gold on a low pop server, what does that equate to on say Illidan - Horde? Hard to say, hard to compare, but it's the main dividing factors of gold makers now. But that's all about to change.
The Dark Below...
Low population servers are slowly getting phased out, and will be completely phased out by the next expansion. One thing that crept up about connected realms that's going to be really interesting from a gold making stand point is that when Realm A is connected to Realm B, you can have 11 characters on each realm for a total of 22 (yes, even post connection), but you see, that's only the tip of the iceberg.
Account Cap on One Connected Realm
Confirmed by this blue post earlier today, in theory, if 5 servers were merged (and they have been already), you could create the account cap (50) of toons on that server. Now I don't know about you, but leveling 50 toons to cap does not sound like fun to me, but if they don't allow 50 toons on all servers the comparison has gone from low pop vs. high pop to single-realm (1) vs quint-realm (5 connected). Fifty potential toons means 100 potential TradeSkill slots, a theoretical army of Alch/Scribes that could destroy gold making empires.
And how about those gold makers who have 2 accounts for cross faction trading? 100 toons. Better yet, if you're not using 2 accounts yet or want to start fresh, you can RAF yourself, and get that 300% XP to level up an enormous army of max level Death Knights. Now, if you haven't noticed the pattern, the level you need to max professions is going to be 85 for the next expansion (it's 80 currently), so having all these toons at 90 would theoretically set you up for two expansions worth of max alch/inscription CDs, although it could bump to 95 if there even is another expansion after this on, but don't worry that's like 2 years from now. It's really a bit excessive. Cooldown markets can now be controlled by brute force, and it's going to be very interesting to see how this all pans out on different servers. In fact, there's already a quint-realm up on live US servers, but I doubt anyone has account cap on a single server yet (although multiboxers probably have previously).
It will be really interesting to see how all these things will pan out. Maybe a big profession announcement at Blizzcon (doubt it) or a caustic environment for classic cooldown gold making in the future, only time will tell. I don't think the average player will be rolling all 50 character slots to make gold, but don't underestimate people, it is bound to happen if it's still a possibility moving forward, and will be an interesting dynamic to watch.
I'm personally still really excited about connected realms, but as you may know if you follow me on twitter, the connected realm fairy has not yet come to little ol' Shattered Halls US. You will know when it does, because it will be all I talk about (hopefully).
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