Regarding roles, I always thought that classes in other edition had one, the only difference is that 4e decided to be transparent about it. I never thought the idea behind them was to make it more gamist, but simply a tool to help players pick and understand the class they're about to play and help make a balanced party if that's what you want to do. Players wanting to cover each role when building their party is no more different than the classic ''We need a cleric'' or ''we need a thief'' in other editions. It's encouraged, but not necessary, I mastered a couple of 4e campaign where not every role were covered and it still went smoothly, the party just changed their approach accordingly, just like in other editions.
So, while I understand that some players don't like things to be spelled out in a way that reminds them that they are playing a game, for me, class roles is a feature and something I would personally like to see come back. It helps to understand how a class will play (especially combined with power source) without the need to look through all the powers and abilities, what he's meant to do to help the party in a fight. For new players, especially in a game with over 24 classes, it's a great tool! You want to play a ranger? well, know that the class is considered a striker, so you should do a lot of damage in combat, move a lot, but have poor defense and/or health so you gotta be careful, position will be important. You want to play an Invoker? as a controller, while in combat, you should have a lot of powers that do area damage and/or debuff the enemy, so it will be about zone control. You would like to be the kind of character that protect your allies in combat and is not afraid to go in the front line? That sounds like the role of a defender, so let's see what classes are considered defenders... you have the fighter, the swordmage, the paladin, the warden, the battlemind... let's dive in those classes to learn a little bit more about them and see what would fit what you have in mind...