i on the other hand would trade my 6811 for a powerbook any day of the week. i keep it as a clean system, updated, and without a lot of junk apps. windows manager crashes on me all the time, unlike finder, but the system stays up. i have far more problems with drivers on a pc, but os/driver integration is a strong point since macs are a closed system. but with any system, mac pc or linux- if you take care of you system, your system will take care of you.
running the latest os x on a rev b imac is rock solid. granted, i know how to maintain my mac better then the average pc user, but thats not saying that a pcer could run his pc as well as i could my mac.
yes macs are good for video editing and dvd burning, and the built in software is superior (IMHO) to the windows equivilents. I am talking free stuff here. 99% of any media files you will have will run fine on the mac, unless you have drm windows media files.
there are p2p apps, most of which are pretty nice. they are shareware apps written by alternate developers so they wont burden you with the spyware or adware that most pc p2p apps would. again, this is not always the case, but the general rule.
there is plenty of software for the mac, and most anyone can get what they need. Games are one area where they are lacking, but unless you are a hardcore gamer that wont be an issue. and if you are a hardcore gamer, you probably have a custom desktop rig, or a console of some sort.
the jump to mac is a big step to a pc user. if you are just a causal computer user, you will pick it up fast. the mac has a great user support base, and getting help is a piece of cake. it wont take long to figure things out, and for the most part, things are the same. the only reason i would say stick with the pc, is if you are an hardcore gamer, or if you have an in depth understanding of windows and the way it works. if you are a casual user, or even an intermediate user macs are just as nice as a pc, perhaps even nicer