There was once a thread where you could post your ideas but it seems to have disappeared, so feel free to post your ideas here (Glyphs or Abilities, anything is welcome).
Here are my ideas:
6% of base mana.
Instant. 8 sec. cooldown.
Your next Arcane Blast, Fireball, Frostfire Bolt or Frostbolt will hit all targets within 15 yards of the target and deal 50% of its normal damage.
1% of base mana. 40 yd range.
Instant. 30 second cooldown.
You place a Frost, Fire or Arcane Rune on the target location within 40 yards which deals damage and causes different effects depending on its type.
A mage-ish version of Traps.
You are able to cast two spells at the same time, but their damage is reduced by 35%. In addition, silencing and interrupting effects are 30% less effective.
Can be deactivated at any time.
(Whether this would work or not, I'm not sure.)
Instant. 30 sec. cooldown.
While the enemy target is afflicted by Arcane Deceit, the next spell cast against you will backfire. In addition, if the enemy uses a healing spell, the latter will deal damage instead of healing.
Lasts 6 seconds.
2.0% of base mana.
Channelled. 20 sec. cooldown.
You burn all targets in front of you within 40 yards, dealing fire damage every second. Lasts 6 seconds.
In addition, enemies affected by Fire Torrent will be dazed and will have their attack speed reduced by 45% for 6 seconds.
Casting Cone of Cold while channelling this spell will cause Fire Torrent to deal Frostfire damage.
Spell Absorption(Possibly Arcane Only):
Instant. 25 sec. cooldown.
When activated, the next spell cast against you will be absorbed and damage taken from that school will be reduced by 45% for 5 seconds.
3.0% of base mana. 40 yd range.
1.5 cast time. 15 sec. cooldown.
You conjure three blades of ice and send them flying forward. Enemies that collide with the blades are damaged.
1% of base mana.
Instant. 30 sec. cooldown.
Any enemy that strikes you will be teleported to a random location 25 yards away from you. 1 charge. Lasts 30 seconds.
(I noticed that someone posted something like this on the official forums.)
Rune of Displacement:
Instant. 40 yd range.
You gain the Rune of Displacement: Vortex and the Rune of Displacement: Exit spells, which you can place on the target location.
The first enemy to approach the Rune of Displacement: Vortex will trigger it, causing all enemies within 8 yards to be teleported to the Rune of Displacement: Exit that you've placed. Lasts 1 min.
Placing both of them will trigger a 30 sec. cooldown.
I think this would be fun to use. Place the Vortex rune at the flag near the lumbermill in Arathi Basin and the Exit rune near the ledge. Enemies trigger the rune and boom, they're all teleported to the ledge and eventually fall to their deaths.
Glyph of Continuum: After a successful Blink, you are able to cast Blink multiple times if within two seconds of your previous one, but the range is reduced by 5 yards every time you Blink. Blinks that follow the first one will not break stuns or bonds under the effect of Continuum.
Glyph of Invisiblity (This would be a nice glyph if Greater Invisiblity was removed): Your Invisibility spell is now permanent, turns you instantly invisible and has a 10 sec. cooldown, but it can be used in combat only once every 3 minutes. In addition, enemies can now detect you.
It would basically turn Invisibility into a stealth-like ability.
Glyph of Brilliance Aura: Your Arcane Brilliance spell causes you to emanate an aura.
Glyph of Magic Dust: Teaches you the ability Magic Dust. Your land mounts can now fly. Lasts 60 minutes.
Glyph of Weapon Channeling: Your spells are now cast through your weapon.
Glyph of Arcane Charges: When you have an Arcane Charge, you generate random arcs of arcane energy. This effect intesifies as the number of Arcane Charges increases.
Glyph of Flame Charge: Replaces Blink. You become a living flame and charge forward.
Glyph of Juggling Fireballs: Every now and then, while you are idle, your character will juggle with fireballs.
Glyph of the Floating Tome: Every now and then, while you are idle, your character will summon a tome to read or one that will float around him.
Glyph of Freezing Mist: Every now and then, while you are idle, freezing mist will swirl around your character, freezing any unfortunate critter nearby.
Glyph of Fire Sphere: Your Ice Block will now appear as a sphere of fire.
Glyph of Flame Wave: Teaches you the spell Flame Wave. A wave of fire will carry you across the landscape. The speed of this mount increases as you move, up to a speed of 100% and will reset if you stop moving.
Glyph of Icy Tornado: Teaches you the spell Icy Tornado. An icy tornado will carry you across the landscape. The speed of this mount increases as you move, up to a speed of 100% and will reset if you stop moving.
Glyph of Arcane Storm: Teaches you the spell Arcane Storm. An arcane storm will carry you across the landscape. The speed of this mount increases as you move, up to a speed of 100% and will reset if you stop moving.
Glyph of Arcane Power: While Arcane Power is active, random debris will swirl around you and the ground close to you will appear as damaged.
Glyph of Relentless Power: While Arcane Power is active, your eyes will glow a bright blue and you will levitate.
Glyph of Arcane Lightning: While Arcane Power is active, your Arcane spells will appear as lightning.
Glyph of Water Elemental Army: Your Mirror Image spell will now summon water elementals instead of copies of you.
Glyph of Arcane Destruction: Killing an enemy with an Arcane spell will turn it into dust.
Glyph of Fire Torrent: Your Fireball will look like a torrent of fire. (Similar to an artwork of Jaina Proudmoore using a fire spell.)
I'll update it every now and then.
Share your ideas and opinions but please, keep it civilised.