Id be interested to know how this turned out for you.  With domain names and tradmarks, it can be so difficult to know what is what, I guess because the new media doesnt always fit perfectly with the old laws.  Anyhow, intresting situation and has me curious.

As far as the URL goes, you don't have any rights to the multiple variations of it unless you purchased those URLs. The online 'best practice' when you are wanting to 'brand' your product and domain, is to purchase all variations of the name. That includes using '-' and also: .com .net .org etc. Once you have all the domains you want to control, do a 301 redirect with your domain registrar to the URL you will be using. This way nobody can try and steal your traffic by purchasing these domains themselves. When anybody lands on one of your other domain names, they are automatically sent to your main URL. The next step for you would be to see what they are selling on that domain. As mentioned above, they may just be interested in your traffic! Otherwise, you need to have registered a trademark for a unique product idea to go after them for trademark infringement. Plano Maid Service -- this post was edited to remove a hyperlink.

I have read up on this quite a bit. I believe Microsoft had gotten into a lawsuit against someone that was trying to profit on their branded name and were using a URL that was similar to their corp name. The best thing to do would be to contact a corporate attorney about your rights. From what I remember, do not quote me on this, they maybe able to use a similar URL, but cannot use your registered name within the actual site.