Most MMORPGs involve a lot of group content (hence the name massively MULTIPLAYER online role-playing game), especially at higher levels. WoW has raids, SWG had missions too difficult to solo, and City of Heroes is extremely difficult to solo after about lvl 20. It could be argued that the group aspect is the point of MMORPGs, but as a casual player myself, I am bored with this mentality. It's not like I want to play the game completely by my self (I have Warcraft 3 for that) it's that I want to be able to solo and have fun.
Let's take a look at the misconceptions developers have about MMORPG content. I agree that MMORPGs should have group content, and I love the challenge and the fun that arises from WoW's raid and heroic dungeon content. It is very well put together and challenging. MMORPGs are largely community games, and aiming towards content that involves a community or group is a good idea, it's just not the only one that should be exercised.
By soloing, I don't mean running through the entire game and never grouping up with someone, nor do I mean avoiding groups at all costs. I enjoy group quests, I enjoy dungeons and instances, but I do not enjoy *having* to do them to advance or them being the *only* source of good equipment. In WoW, you can either run heroics all day, or PVP all day to get "good" equipment. Why not make some solo quest lines or something that lead to equal equipment as to what you would get from raids? They should be difficult, and take time to do (roughly equivalent to how much effort it takes to get them from raiding) but can be done completely solo. It would be difficult to balance and impliment, but then again, it's been completely ignored for the sake of raids.
I imagine a system could work like this: You do a series of solo quests, gather rare reagents (all found out in the world, not in dungeons), perform some sort of ritual, a spirit is summoned, it asks you to do 3 quests in exchange for an item of power, you do those quests (which all have multiple steps and time requirements, and maybe reagents), he gives you a sealed chest, and inside is a random BOP epic item that would drop from a raid boss. Now I have two thoughts about this, making the quests harder, but being able to select which raid or which boss even the loot table is drawn from, and making it basically drop loot from a random boss (so multiple epics, and a chance for the really cool and rare stuff) but no selection of what raid or what boss.
Again, these quests should be interesting and require as much effort (or perhaps more) than the effort required by each raid member to down a boss. There should be timers to repeat the quest and for certain parts of the quest so that epics can't be ground out any faster than a raid. Let's face it, it's a good day if you get one pieces of epic equipment from a raid, let alone an entire boss drop. Most of the stuff dropped in my example will be useless and disenchanted or sold. Also, put the quest timer on a global cooldown with all raid timers. You can pick one, you can't do solo epics and raid epics.
Another thing that bothers me about MMORPGs is the lack of development of the basic quest lines. These are quests most players play through, so there should be some development to them, but they are largely badly written and have dubious reasoning. "Go kill 4 wolves, because I hate wolves." etc. I want quests that bring me into the world and make me feel that, even though I'm a newbie, I'm a newbie *hero* I don't think it's that hard.