Erm, Within Temptation has been around for longer I think, and they're not imitating each other, they're both just hitching a ride on the kiddie-gothy-pop music trend that's been going on in the past years.
I actually helped WT get where they are today [img]tongue.gif[/img]
When I first met them they hadn't played more than four gigs in their entire career, and I was in the promotion team that had to get people enthusiastic about them. They've gradually been gaining popularity everywhere, but in the Netherlands they've been well-known for several years.