For a start, it's a reminder (commemoration? Celebration? Not exactly...) of attempted treason, of the largely-indiscriminate mass-murder kind. Secondly, we do the whole "Guy" thing on the 5th - but the 5th is when Guy was arrested; his actual execution was early January.
Thirdly, the traditional childhood activity is burning in effigy ---
One more time, for those at the back: that's burning in effigy, kids.
--- while Fawkes was actually hanged.
I've mentioned this a lot to various folks, but this year is the 400th anniversary. I do hope the Beeb and co. have their act together -- it should be a big 'un. I did write a story meself towards the end of last year, but unfortunately, did so in a godawful way, so it was a really crap story; haven't gotten around to doing the rewrite yet, alas. Pity - I liked the (ahem) plot.
And V for Vendetta isn't due out until, oh, March or so next year. Which is probably a relief. If Moore's not happy with the script, I'm not gonna be. V is one of my favorite comic books; I've read it many times. I really don't want to see Hollywood butcher it.