Signet of Illusions

Signet of Illusions is a skill mentioned in the Guild Wars Nightfall pre-order booklet. It may be an unlinked skill, as its description states:
 * Activating the new mesmer skill Signet of Illusions allows you to use your Illusion Magic attribute on the next spell you cast.

So, the next spell you use counts as an Illusion Magic spell, causing it to use your attribute rank in Illusion Magic as opposed to its actual linked attribute. For characters investing in Illusion Magic, it may be worthwhile to spend a skill slot rather than attribute points to power a non-Illusion Magic skill or useful in combination with skills such as Inspired Hex, Inspired Enchantment, and Arcane Thievery.