I have not earned anything from this domain yet. But it is just a 2 months old.
About the trademark issues you are right, most of the people have suspicions about them. But they have advantages like being well-known and they can be the first address if you make a website about what it reminds people. For example if you want a forum about office softwares this is a good name to use especially in India.
In Turkey there are excel forums like excel.gen.tr or excel.web.tr and i don't hear anyting about trademark problems from microsoft so far.