Well......
There are a lot of reasons why we should bring up previous editions, especially in a proposed unity edition. I also believe that balance is important, not at the cost 4e incurred which was to me, classes playing relatively the same. Others disagree, hence the talk about editions.
I believe that classes should be balanced. But not strictly ONLY balanced with combat. I believe that the skill needed to sneak into a castle, and the skill needed to sweet talk a king is just as useful as the skill needed to fry an orc. As a DM I have seen characters with strong non combat skills bypass whole dungeons and have awarded them the XP for bypassing that encounter (following RAW and RAI as I see it).
I believe a D&D that gives the players a variety of abilities makes for more fun and engaging adventures. I also believe balancing across a range of features allows for truly different class options and not just a tacked on skill and non combat system that doesnt feel a part of the "one true combat system". I believe that 2e, 3e, and 4e had illustrative examples on why with this was so and we should take the best elements of the past to form a better DND-Next.
So I believe when you say "It should also be mentioned that it is not necessary for balanced classes to be the same as one another" you need to be more specific. If all classes follow the exact same progression, use the same amount of powers, gain powers at the same time, and have relatively simple, mostly combat powers then the game will be very balanced. But I personally believe that the classes will "be the same".
What degree of balance do you mean exactly? The kind where its somewhat balanced in a VARIETY of situations but of course there are exceptions and errors that should to be revised and errated on occasion (a la 2e and 3e?). Or the kind where the classes are very very balanced but some people think the classes are too similar and the balance is at the cost of focusin only on combat (a la 4e)? It's easy to say your for balance and different classes, but its a lot harder when you start taking into account the different ways classes progress, act mechanically, gain powers, and act in a variety of situations.
Okay fair enough -- you make a valid point regarding there being a need for some reference to earlier editions.
Now as to a balance -- I am in complete agreement that balance doesn't only have to be a combat thing and that balance can come in the form of skill benefits or other areas. That being said, combat is a big part of the majority of campaigns and as such all classes should be able to contribute in meaningful ways to the fight.
To be completely honest I don't have the answer I am simply stating what I would like to see in an ideal game. I do understand that there are certain sacrifices that need to be made in order to get a balanced set of characters.
As a side note and yes a reference to earlier editions and complaints of a lack of balance --- I have never been all that unhappy with how balanced any particular class was in any edition. Nor have I felt that all the classes were the same in 4th Ed. Although I generally DM when I play I have never been interested in playing Wizards and rarely interested in Clerics. I usually play a fighter or rogue and I have never felt like I wasn't contributing. That being said I am a min/max type of player (I also love to role play) and I have a fairly large personality at the table so I really don't ever feel left out.
Finally I am not a game designer (although like most of us I do tinker) and I cannot spend all day trying to work through this problem. I am going to put my trust in a very talented group of people and hope that they can come up with a solution that I find satisfactory. If they don't then my solution is simple -- I do not need to buy.
Finally I would like to say that I hope nobody was offended by what I said earlier and that I always enjoy reading posts on ENWorld -- I may not always agree but it is nice to see such an active group of people all of whom a trying to make the game we all love better. I would encourage everyone to throw their two cents worth in any time they have something to say --- it's kind of like voting if you don't participate in the process you have no right to complain about the results.