What? According to Verant's own definitions all Melee classes have Dual
Wield.
In fact, of melee and hybrid's only Paladins and Shadowknights don't have
dual wield. This is a totally bogus excuse for changing this spell. This
is another in a long line of ridiculous comments from VI. When was the last
time you heard somebody at level 50+ desire a ranger in a group over a
paladin?

After a great deal of consideration, we have concluded that the Mark
of Karn spell is imbalanced and requires correction. This spell's
current function makes melee classes without dual-wield far less
desirable members of the group. As such, the spell has had its
duration decreased, its recast-time increased, and its "heal per hit"
value decreased.