A couple of quick responses:
@Dan, you can mix either melee class with a caster successfully. The most popular seem to be warrior/mage or mage/thief, but I've seen druid/warrior or necro/warrior work well.
Some comments in response to the druid critique:
1. Druid spells cost more because most mobs in game are not resistant to a great deal of the damage types put out. Gust for instance is a breath attack, and very few low level mobs (where you're using gust most often) are resistant to breath damage.
2. Preparation for druid spells. The spell staff skill allows you to pour a lot of those high mana spells into staves. One spell staff of control weather and that 300 mana isn't coming out of your fund right now. Also too, if you do travel in groups, druids can work together to avoid this problem.
3. Sun catchers are not the big time sink and pain in the butt that I'm hearing. Before I leave game I hide 8 or 9 catchers if I've used that many (rarely). At the beginning of the next game, I gather. If you are not a min maxer and don't wait for optimal fill, it's no more of a time sink than creating necro minions is.
4. Druid minions are good for some stuff, and a lot of their utility or lack of it has to do with the player in the similar way that necro tanks suck when used against the wrong damage type. The bears for instance are decent tanks, and polar bears at high levels have in excess of 1400 hp. Yetis are good in this respect as well. Further, at higher level, druids have a number of possibilities for a quick tank with earth wall or shambling mound. NO, neither is optimal, but they both are good as hide behind mobs. Druid minions, the tank minions, hit much better than their necro counterparts, and live oaks have hands and can be loaded up with hand spells and they make decent tanks for most midlevel things.
I've run several druid primary combos. None of them are high level as of yet, my highest is tot 106, but they're getting there. The biggest issue I run into with druid is just corner cases: underwater, underground, etc. However, even in these cases a druid, at higher levels, is not completely helpless. Thunder seeds works underground as does a number of the vine spells. In water, call waterborn gets you some very nice minions. The sun spells that use sun catchers can be useful as well if you're not the one tanking. If you have paired druid up with another class with damage dealing magic, then in those situations you switch to flame strike, ice bolt, or w/e and move on.
Many people brought up the issues with people giving different advice due to play style, and this is a good example of that. Necro and druid both are minion classes, but they have a diferent set of emphases in their minions. At high end play, a lot of people are dissatisfied with minion classes, and with some justification. The recent changes to areas to make them group worthy have made minions a more difficult matter, however, even in these situations, scrolls or other items with protective spells on them that can be used on another come in handy. Alter is not primarily solo play driven, and Dentin has been working hard to tilt it more toward group play. For those of us who prefer smaller groups, and/or, solo play have found this frustrating. However, one thing to keep in mind is that this change came about because a number of high end players were complaining that their experience was denting because they were running the same half dozen to dozen areas repeatedly. The dent giveth, the dent taketh away.
As to any one class, or class combo being predominant, I tend to see that as if true an ephemeral truth. When I started playing ten years ago if you did anything other than mage primary you were insane. A lot of people thought for a while that necro was the most dominant class on the mud. The classes are becoming more balanced, but they're balanced in relation to each other both as first second third choices and in terms of grouping. That's something to keep in mind as well.
Having run with several people who have druids to level 37, I can say that I am not seeing them totally sucking compared to everyone else. However, I don't pretend to huge amounts of knowledge about what the current best build or best method of dealing with X is.
Take care,
Jeremy