Actually what draxynnic said has me a bit concerned about this idea. Cutscenes depend on the players being in them most of the time. If you let people skip it and run freely while the cutscene is playing, that could screw it up, maybe even bug it.
Imagine the Lich walks to the portal saying "it won't be long now... not long at all," and a warrior runs up to him and /taunts and /dances in front of him. Then suddenly he stops walking because the warrior blocks his scripted path and the cutscene never ends.
While I think that would be hilarious, I'd rather it not happen. The cinematics are buggy as it is. Adding this new variable could be disasterous. What happens if the leader of the group - the one who's seen following and talking to Master Togo in the cinematic, skips and leaves. Then we either have nobody there or ANet needs to put in extra code to elect and teleport in a new leader into the cutscene.
I think cutscenes have to work as they do now... though as has been requested hundreds of times before, they need to freeze people's health and mana.