Actually, it will. And that's coming from a long distance runner who has dabbled in strength training for about five years. I cannot put on any significant amount of muscle when my mileage is in the 30-40 miles per week range. The only time I have been able to get my bench press up to 225 was when I significantly cut my mileage back (under 30 miles per week). There definitely is an inverse relationship between significant cardiovascular exercise & significant muscle gain.
That being said, I would recommend a certain level of cardiovascular activity for everyone, even skinny fucks like Matt, if for nothing else than heart health & not losing your breath when you walk up the stairs.
My ratio of cardio to strength training is high (much more cardio) but I've found that this makes me feel good, and I am more inclined to being an endurance athlete than a hulking mass of muscle. Everyone's different, though.