The approach to take in fighting the trademark is that bitcoin is a generic term for describing actual bitcoins and as such is already in the public domain...
"Trademark rights can also be lost through genericity. Sometimes, trademarks that are originally distinctive can become generic over time, thereby losing its trademark protectionKellogg Co. v. National Biscuit Co., 305 U.S. 111 (1938). A word will be considered generic when, in the minds of a substantial majority of the public, the word denotes a broad genus or type of product and not a specific source or manufacturer. So, for example, the term "thermos" has become a generic term and is no longer entitled to trademark protection. Although it once denoted a specific manufacturer, the term now stands for the general type of product. Similarly, both "aspirin" and "cellophane" have been held to be generic. Bayer Co. v. United Drug Co., 272 F.505 (S.D.N.Y. 1921). In deciding whether a term is generic, courts will often look to dictionary definitions, the use of the term in newspapers and magazines, and any evidence of attempts by the trademark owner to police its mark."
Thats pretty much the whole point. I for one don't care so much about the Bitcoin community having a trademark since it should not be neccesary. The problem is somone else having potential to cause harm to Bitcoin users or businesses because they have one.
And yea, the .com thing was a side track from the whole trademark issue. Thouse, certainly a .com would be much more succeptable to trademark dmg than a .net, etc as was pointed out.
And, trademark and patent are two very different things and I see where people are confusing the issue of this trademark as it relates to the Bitcoin itself and talking about the software, though not applicaple, would fall under patent law if it were.