So since Riot is reworking how Spellvamp works on WotA...
I figured I would toss this suggestion out there.
Instead of making Spellvamp only provide 33% healing on AoE abilities, make it instead pick the highest single heal value from a given proc and heal for that. In effect, all healing would be single-target healing. This would allow Spellvamp to be useful on champions with mostly AoE abilities rather than only being nice on the folks with a bunch of single-target spells.