If the proposed changes are carried through with anything like the current mechanisms, I would like to offer my opinion that the goal of making heavier armour types more useful is currently being approached in almost exactly the wrong way. As has been noted before, apart from parry mages, other casters compromise on Dex and hence stamina because it is not essential to their template or damage output. Dexers, on the other hand, have to work all three stats to be effective in both PvM and PvP. Mana is just as important to dexers as it is to mages as all forms of healing outpace non-special hits from a mana-poor dexer. In such a matchup, the mana depleted dexer has no realistic chance whatsoever of killing a PvP opponent.
PvP is about timing the delivery of burst damage for both mages and dexers with various added tricks to disrupt healing and a few other bells and whistles. This requires mana and I believe that due to this mechanic, mana - both as a deep mana pool and good MR, is actually MORE important to a Dexer than stamina. If you don't believe this, try running an Elven Dexer with no MR - there is an awful lot of downtime. This is the reason leather armour became the only workable choice and it is likely to be the reason that, even if the stamina changes go through, leather will remain the required armour type. Passive mana regeneration is indeed compromised severely when wearing non-medable armour whether you have Meditation as a skill or not. Let me illustrate through some recent quick and dirty testing:
Template with 90 Int and 13 MR from kit (no Med skill as Elf) - to regain 100 mana takes 91 secs wearing medable armour, 112 secs wearing one non-medable piece.
Same template with 20 Med skill (equal to JoaT Med) and 11 MR from kit for a total of 13 MR - to regain 100 mana takes 84 secs in medable suit, 127 secs wearing one non-medable piece and 63 secs actively Meditating
A Dexer in non-medable armour will take therefore approximately 33% longer to recover mana than a leather armoured Dexer. There is a slight difference between 20 Med/11 MR and 13 MR as MR from Meditation seems to be more effective. This mechanism is also affected by total Int and doesn't scale linearly - but that's another story.
What this means is that a Plate armoured Dexer will be slow to regenerate mana and in open field combat, will rapidly risk becoming ineffectual as he will not have the mana to power specials. Stamina loss does not come into the equation because that CAN be recovered rapidly (although slower than before) through a variety of mechanisms. Until the moment of combat, Stamina is only important if it stops you moving and so Refresh potions will have to be saved for this purpose as it will very likely be a matter of life or death. In comparison, there are very few practical mechanisms to regain mana rapidly in PvP.
This will force Dexers to consider running Meditation as a skill (few apart from some archers do so currently) compromising already cramped templates which will likely reduce their effectiveness. The alternative will be to bow to the inevitable loss of stamina and run a Nodexer (TM - I said it first!)
template - run 125 Int and enough Str to hit 150 with kit, dropping Dex and Stamina to the minimum and rely on SSI to swing fast swing speed weapons at 1.25 - this can be done with zero Stamina. Since Stamina loss is currently a percentage loss, this can be accomodated with standard Refresh pots as before. Paradoxically, this may actually be a stronger template in the new environment as it will be capable of running a mana pool of over 200. What will have happened is that weapon choice will become more limited for the leather wearers and skill templates for the heavy armour wearers will become more limited with the need to maintain mana regeneration. We will see less variety, not more.
The pressure to wear heavier armour will also severely compromise all stealth templates although I will concede that is very possibly an unstated goal...
Solutions? I do have some suggestions but I would like to see if there is any agreement with the thoughts above before I burden you all with any more. Some things to think about though:
1. Heavier armour should (logically) provide more protection from damage, If anything, it should reduce Dexterity (and hence stamina). Introduce bonuses and penalties to reflect this. In RP terms, the thieves and leather wearing bandits are capable in melee due to to lack of encumbrance but use only lighter weapons. You have to have trained (Dex and Stamina) to be able to wear heavy armour with it's greater protection without losing too much speed.
2. Heavy weapons - a bonus to damage or an automatic stun/concussive/stamina draining effect should be attached when wielded by someone wearing heavy armour ( much in the manner that Splintering works). The rational is simply that there is greater weight behind the blow tranferring to the point of impact. This alone might make up for many of the issues arising from slower swing speed.
3. Dragon scales - use as enhancing material but treated as leather. Bonuses obviously to different elemental resists.
4. Casters - should have a FC penalty scaling off stamina remaining. I KNOW that a zero stamina caster would then be a sitting duck - but so is a zero stamina dexer under these proposals. Let us please have an even playing field.
5. Archers and to a lesser extent, Throwers, will be dead with the proposed changes. Their weapon speeds simply have to be faster.
I would like to think that we might see the emergence of more varieties of melee templates as a result, not fewer as I fear might happen.