Not necessarily. If you want to add a paladin who is ret-specced, you might need to swap him with another melee class (which translates to a rogue or maybe a warrior if you had two warrior in one melee group) - especially if your groups were already optimized.

Yeah 5-mans have always been my favourite thing in this game as well. Sadly I guess you just have to accept that the game is about character progression and getting more and more powerful items; this means all content will be slowly phased out and made irrelevant (booring) even if there isn't a level cap increase.

As noted quite a big positive point of the 5-man game is that with 5-mans there are plenty to chose from and you get a varied experience. For myself I don't think I have done any particular heroic more than once every 2-3 weeks. That the experience is varied is part of the fun for sure.

Blizzard could of course add Heroic Stratholme and tune it for a higher item level compared to the other heroics; but then you'd only have one instance to go to and be challenged. Doubt that would be fun for long. Much of the point with heroics now are just that you can chose between multiple ones that all are tuned for about the same item level. As long as gear is appropriate its great; but of course after some time gear is too powerful and all of them stops beeing fun at the same time more or less. Sure Shattred halls and Black Morass maybe fun a little longer than Underbog but difficulty difference between the heroics isn't major really.

Anyway the problem with 5-mans and progression is probably that the people want challenging 5-mans really don't want to have the instances that are progressively harder; so you work on one instance at a time until its tome to move onto the next; but really wants a good many different instances all on comparable difficulty so you can chose where to go.

So Blizzard really can't just add another harder instance every other patch like with Raids. But would rather need to add a new difficulty setting, perhaps Legendary mode, and retune a good number of the existing heroics for a new higher item level so they are once again fun and challenging.

Of course just retuning an instance for higher item level isn't exactly a new experience so we'd still want totally new instances as well.

Not sure if anything like that would even be managable. I mean make one new instance in normal, heroic, and legendary mode. And take maybe 10 of the existing instances and add a legendary mode to them as well. Would be lots of work on retuning old content.

And of course after another two months when gear inflation worked a little legendary mode obsolete once again and its time to add maybe Deathwish mode or something; and retune everything once again....

Would assume that in the end you either have an end-game with lots of options that lets you chose what to do each week and grants a varied gameplay experience, but without much character progression in terms of better and better stats; or you have an end game with progression that makes old content obsolete with time and tends to pidgeon hole players into doing the same instance over and over again.

Not sure what the best model is. Stat progression seems to be a powerful lure to drag players through content. I don't think its really possible to combine a good 5-man game with item inflation since the amount of time spent on constantly retuning old content to keep up with item progression would be pretty significant.

Not to mention having normal mode and heroic mode now is really enough of a hassle with forming groups with people wanting to do different versions. 3 difficulty levels would add more trouble.

Would be intressting to see if an MMO could survive without item mudflation, or even level cap increases, by just adding more and more gameplay options to the world. But never allowing item/power progression to phase out any of the old content so the option to go there for a challenge remains. World of Warcraft wont change in that respect though of course.

In general the game would probably be better off if classes default abilities were more robust, and their talented ones were toned down. But this would also be an immense project and would introduce a lot of potential balance issues. But I mean things like:

-Warriors/paladins/druids could have all the baseline abilities needed to tank anything. Talents would focus on improving them and increasing damage reduction, rather than giving defining abilities (like holy shield, mangle, shield slam, etc)

And the same basic thing with healing abilities and whatever else for hybrids. Now obviously you'd still want particularly specced people for certain jobs, but you would get a lot more flexibility if you could pull this off. It does have a rather huge problem in terms of itemization, though. Itemization is just as specific as talents, if not more so, and it's really not realistic for classes to be expected to have 2 or 3 sets of top-notch, enchanted gear ready to do multiple jobs at once. So you end up back where you started at specialized talents using specialized gear for specialized roles.

Feral druids end up working so well because they get defense AND offense from many similar stats far more than other classes (both Agi and Str, for example), so they really can pull off two things at once. Paladins, priests, warriors, shaman, and other druids aren't even really close to this kind of gear synergy.