Think of the accidental traffic you'll get?
I was going to register a .IE domain name today. It's a niche key-word based domain and I'd spin it out as a micro site.
Unfortunately, the .COM version redirects to a porn website.
Would you write off a great domain because the .com is taken by an 'adult publishing' company or would it matter to you?
I'm thinking it over and I'd have to say no
I go to dot coms first from memory and then .ie domains
if people were to end up on a porn site looking for your microsite would it hurt your business ?