These are just some of the changes I'd like to see in the future Eldar Codex:
Misc' Wargear changes:
Plasma Grenades: either both offensive and defensive to match description and/or boost to strength 5 against vehicles like in 4th edition.
Wargear for Warlocks and Exarches:
Waystones: a unit with a waystone doesn't need to be in range or los to benefit from a farseers psychic power
Runestaff: a two handed power weapon, if the farseer can cast a second power the farseer can cast the same power twice.
Forewarn power: Range 6", a unit that this power is cast on may make a free round of shooting at a unit arriving from reserve in the following opponents turn however if they choose to do this they may not fire in the next eldar turn.
(Amendment made based on sonsoftaurus's comment)
+1 Iniative and Leadership to match aspect warriors.
Spiritseer becomes a power not an upgrade.
Bonesinger becomes a power.
Enhance adds 1 to ballistic skill as well.
Master Strategist: replace "has a strategy rating of 4" with "can steal the iniative on a 5+"
Witchblade becomes an option.
Court of the Young King:
A honour guard for the Autarch
Shrine Leaders: for each exarch in the court the player may take a bonus unit of that exarches aspect, this unit doesn't take up any force slots.
Pathfinders become like exarches for rangers with exarch like stats. Pathfinder and master of stealth rules becomes its powers and Poison pack (poison close combat attacks)one of it's weapon upgrades.
Fast Attack Changes:
Death spinners gain rending (if the nightspinner is anything to go by this is confirmed)
Roll a D6 on second movement and on a 1 lose a member instead of 2D6 and a double. Allow full 12" movement, more worth the risk especially with autarches.
Heavy Support Changes:
Wraithcannon an optional replacement for flamers/shuriken catapults.
Shadow weaver gains rending.(if the nightspinner is anything to go by this is confirmed)
Craftworld tailoring rules for characters
Biel-Tan: Aspects count as scoring units.
Saim-Hann: all Jetbikes and skimmers gain the scout rule.
Ulthw'e: All psykers may take an additional power.
Alaitoc: May steal the iniative on a 3+.
Iyanden: All psykers add 6" to see if they are in range for wraithsight.