Simple idea to make you want to play support :)

http://pre01.deviantart.net/b210/th/pre/f/2013/098/4/a/league_of_legends___supports_wallpaper_by_xmarquinhos-d5aq1xg.png

Boots of Mobility

• Increase the basic mouvement speed to 45 from 25

Create new potion only for support:

• Cost 150
• Includes 3 charges
• Restore 100 life and 30 mana over 12 seconds
• If you attack and take damage during this time the potion is canceled

Zeke's harbinger

• 50% critical strike is replaced by 20% attack damage
• The effect is only activated by attacking an enemy champion

Banner of Command

• Actually unique active is removed
• New unique active: immune an ally for 1.5 seconds (120 second cooldown) (Just to give a Zhonya support version because currently they are too expensive for them)

Sightstone

• Add unique passive: Destroy a ward restore 1 charge (60 second cooldown)

The upgrade gives 3 ward now (because sightstone up)

3 maximum charges now (because sightstone up)

As is the case for "ambient gold" just create a "ambient experience"

• After 12 minutes, the 2 members of each team with the least experience receive free experience every 5 seconds

Recovery (Mastery resolve) only for support now

• 2 health per 5 seconds is removed
• Now give 4 health per 5 seconds when out of combat for 5 seconds

Create a new final mastery in Cunning

• When you slow or immobilise an enemy champion his defense and magic resistance reduced by 10-25% for 1.5 seconds (based on level)