There are two long-standing deviations from the D&D rules which I would like to see remedied in the near future, maybe even for Mod 6.
The first is Spell Resistance. Each and ever spell in D&D is specifically flagged as being Spell-Resistible or not. But DDO went through and said that every single spell that deals direct damage ignores spell resistance. This is problematic for several reasons.
One of the things that always gets said about this is that it's to benefit PC spellcasters. That is, quite honestly, a load of hooey. Given the vast disparities between PC and NPC hit point totals removing ways to block hit-point-damaging spells benefits NPCs far more than PCs. As a PC casting on an NPC, one searing light here or there is relatively insignificant. As an NPC casting on a PC though, one searing light can be 10-50% of a PCs hit points. Thus, it becomes obvious that defenses against HP loss benefit PCs more than NPCs and therefore goes to follow that removing those defenses benefits NPCs far more than PCs.
In addition, it mucks with a vast variety of other effects. Why, for example, is Spell Resistance a fifth level cleric spell when it blocks so few things in DDO. Though, again, you see the disparity here. Things like Spell Penetration remain fairly valuable to PCs because the spells we want to cast on enemies are non-damaging (or insta-death) spells and therefore most are subject to SR. But the SR spell or a drow's SR are significantly weakened because they don't protect against the critical damaging spells.
Please restore spell resistance to it's D&D state, and remove the overarching "damaging spells ignore SR" logic.
The second thing I'd like to bring up (again), is Antimagic zones. With level 15 on the horizon, that brings 8th level spells, one of which is Antimagic Field, so it seems like now is a good time to reexamine this game feature again.
An antimagic zone suppresses spells, spell-like abilities and supernatural abilities. Currently, the only antimagic zones in the game come from Beholders. Currently, those antimagic zones dispel spells and permit spell-like and supernatural abilities. This allows the beholder to dispel all your buffs and then hit you with eyebeams, when in fact at any point in time that you could be hit by an eyebeam your buffs should be in effect. Further, one of the main uses for Antimagic Field is to prevent spell-like and supernatural abilities from affecting you, so it's pretty imperative that these get added to the list of things that antimagic blocks before the spell gets added in.
So, please also restore Antimagic to work in accordance with the D&D rules, suppressing (but not dispelling) existing spells and blocking both spell-like and supernatural abilities.