Good example to look at:
The yet to be released game Diablo 3 created by Blizzard inc.
before Diablo 3 was announced officially, there was a website titled diablo3(dot)com
a few months before the official announcement, Blizzard contacted the owner of the site and (politely, in no means rude) asked him to basically relinquish the domain name to them simply because they owned the rights to it, they compensated him very well and everything went very smoothly, however, this is what you have to understand:
If its an exact match to trademark or copyright, they CAN take it away legally without paying you a dime.