Rule one. If its important enough to register a .com, its important enough to trademark.
I lost one I cared a lot about, not to squatters, or "enemies" but to guys I knew, respected and did business with because I got the .com and they got the trademark, both of us assuming that later on, we'd get the respective missing piece. Fortunately, neither of us was spoiling for a fight with the other so it was resolved amicably.
Trademarks trump ICANN registrations (to the point that ICANN will take your .com and give it to the trademark holder).
About the only thing having registered the .com before someone else trademarks it will get you is the ability to charge more to the trade-marker to sell him the .com.
