the April 14 issue of TV Guide has a little table comparing Buffy the Vampire Slayer to ER to show how the two shows are becoming more similar:

Buffy	ER
Popular and sympathetic mother Joyce Summers develops a brain tumor.	Popular and sympathetic father Mark Green develops a brain tumor.
Established heterosexual Willow, the reheaded witch, goes lesbian.	Established heterosexual Kerry Weaver, the reheaded bitch, goes lesbian.
A brooding foreigner with a tragic past, Spike, replaces a hunky American as a love interest.	A brooding foreigner with a tragic past, Luka Kovac, replaces a hunky American as a love interest.
Olaf, a large and bellicose troll (played by actor Abraham Benrubi) wreaks comic havoc in the magic shop.	Jerry, a large and bellicose desk clerk (played by actor Abraham Benrubi) wreaks comic havoc in the ER.
A petite and attractive woman mysteriously appears in Sunnydale. Surrounded by a cache of minions, she sucks the brains from humans during her maniacal march toward world domination.	Sally Field gueststars.