Is there going to be a need for the typical tank and healer style group in eso? Tanking has always been a lot of fun for me and I'm worried that the class system is going to take away from that.

It shouldn't take away from that at all. The different classes support different roles. DragonKnight-Tanker. Templar-healer

We do not know yet, they were trying to downplay it, but probably didnt workout so well (think of GW2 mess)

There are no class roles, any class can tank with Heavy Armor + Sword and Shield skill lines and any class can heal with Restoration Staff + Light Armor skill lines. Class skills just add some more flavour and choices

Healer, definitely.

Tank? Most likely.

Well I mean I know they'll exist, my concern is mostly with whether or not they will be as crucial as they are in other games.

That is optimistic enough for me!

We don't know much about AZs yet, so I have no idea, but given the nature of how aggro supposedly works and that they want people to sort of "handle their own" in some situations in dungeons tells me that DEDICATED tanks (as in a dude setup primarily to tank and nothing else) might be unnecessary in smaller group settings depending on the layout of the party (as in you got some pretty sturdy dps that can take a hit or two).

But I can never really envision a situation where not having heals is a good idea.

The classes don't really matter ,but it seems like they lean towards certain roles.

The developers have said a number of times that they are aiming for a situation in which things can be done without the holy trinity per se, but that you will normally have an easier time if you use it.

This approach sounds particularly good to me as it is reminiscent of Vanilla WoW which afforded much greater flexibility in what specialisations could fulfill the tank and healer roles. This fits with ESO's class design structure of more flexibility in how people want to build their character.

I disagree. Anet made a very good combat system, but, it works better with larger groups and they don't realize this. They, instead, focus on small scale combat that doesn't take advantage of combos etc.

This said I think they have come out and said there will be healing and tanking, but it won't have as large of a impact on things as it did in games like WoW. Basically think between how things were in GW2 and WoW.

Threat generation works differently than it does in, say WoW. They aren't doing away with the trinity like GW2 tried to do. You still need a tank/ tank hybrid and healer/ healer hybrid for certain difficult encounters.

I imagine that hybrid type characters will be fairly popular.

From what we know, the Dragon Knight class will have a skill line for tanking. But there will also be other skill lines for tanking that are not class related.