Not necessarily full-round; full-attack would cut their movement, but not make it so easy to interrupt them. Full-round = start casting now, takes effect on your next turn. Full-attack = start casting now, takes effect now, but no more than a 5-ft. step is possible.

You know, just cause everyone keeps bringing up the "old school" extra attacks I seem to remember the chart being thus:

1~6 level 1 attacks / 1 round
7~12 level 3 attacks / 2 rounds
13+ level 2 attacks / round

And the fact that you could only move up to half your movement (movement rating x 9 feet) and still get a melee attack...

Add to this the fact that a combat round was an entire minute long.

how long a combat round in meaningless in a make beleive world.

however "pew pew pew" and run around makes no sense when when you cant swing a sword and run around.

Interupting a spell should be POSSIBLE at least and multi melee attacks per round should be possible and still do a full move.

If ?I run up to your wizard and do a full move, I can attack once (and its neraly impossible using core rules to consider the fact that Ill actually interupt a spell.

The following turn, if I win init, then I can tool your wizard with a full attack.
The problem comes about, that the wizard can run away and pew pew pew. The fighter, trying to follow him, would on get that one attack, and if the wizard was good with his spells (charm, hold, whatever) once he got the spell off the chase was over.

Mind effecting spells should not be pew pew pew, Confining spells (hold, entangle etc) should not pew either. Area of effect spells should not pew.

Now if you want to pew pew pew away with magic missle,even lighting bolt (technically an area of affect) or the like (beams go pew) then you can do that as much as you like, or as long as you have spell slots for it.

IF the wiazrd can run around and pew pew pew, the fighter should be able to chop chop chop.
But if fighters get this fix, then so do monsters, which technically changes their lethality in the game.

So there are pros and cons ,nerf the casters with longer casting times.
which would be the easiest change,but then you are nerfing which everyone cries about.
OR Fix melee movement but then you have leaping, bounding, backflipping monsters runnign around through your party (which 3.x players simplay arent used to and would say is fair.

There is one more option: a feat or feat tree (if necessary) that you could get for characters, however every tom, dick and harry troll out there isnt going to have these, in which case players have a movement edge on their adversaries (which they should) only the extremely mobile or powerful monsters would get feats like that.
Im in favor of giving something to the PC's and not giving it to every monster and NPC out there. (or the idea that a monster with a ton of natural attacks could pick up a useless rusty dagger to suddenly become a movement machine by trading iteritive attacks- which is 100% metagaming rubbish)

I don't want to return to 1e-style mechanics with class-specifics. I just want people choosing to melee to be able to do so without becoming irrelevant, and not just fighters.

Rigid class properties are one of the big reasons I abandoned AD&D for Runequest (no classes) and Rolemaster (classes as aptitude templates), both of which are skill-based. Skills and feats brought me back to D&D; although I'm still uneasy about class features, they are 'traditional' in D&D, so I can live with it if they don't become more important.

Also, unless you add some other stuff, at most this means taking a one-level dip into a full-BAB class. Or would you insist on multiclass characters only having full-BAB components? That's nasty and you'd add exclusions for the Eldritch Knight, etc, so it'd become a patchwork of additional rules like monk and paladin multiclassing restrictions in 3.5 splats were (and thank God Jason ditched those).

If you really wanted to talk about First Edition style of mechanics, then everyone--repeat EVERYONE--would only get one attack accept for monsters who got the venerable 'claw, claw, bite' attack action.

Unearthed Arcana ushered in multiple attacks at the end of First Edition just prior to the 2nd Ed. 'reprinting' of AD&D. It could be argued, even at those early years of the game, the fighter types were getting the short of of the stick when it came to damage output. Of course, that was long before dice caps on spells. Then 3.X came along and all the classes could attack more than once per round, once again relegating the fighter types to the bottom of the damage output scale once again.

So in short, I'm not advocating going back to hallowed First Edition mechanics, I'm just saying we should pull back a little on the non-fighter types in order to bring the fighter types up to scale with everyone else.

I hope they do something about casting times as well because I have never heard of a viable spell-disruptor character since the days of the very first Unearthed Arcana. There are far too many things casters can do without any form of check-and-balance.

The length of a combat round is very relavent to how much a character gets done in it.

You really can't complain about the amount a spellcaster can get out in one breath during a round then turn around and say the length of the round doesn't matter.

If one round = one minute, the spellcaster moving and getting a spell out isn't that big of a deal. In that same round a fighter that can't get more than one attack in and move is a rather silly.

If one round = six seconds, the spellcaster getting some spells (not all I agree) in each round is believable (not the long ones though), while the fighter running around and taking 4+ attacks is a bit more odd (Cloud strife anyone? How about Tidus?).