This would be amazing if it came off; plus people would travel from all over Europe for it, and the Devils would benefit from the buzz. American football sells Wembley well, and that's like watching rugby league with a child with ADHD pausing the action all the time.
Thing is, I just can't see it. The market doesn't seem to be there in the UK. If everyone who came to all games across all leagues here turned up, you wouldn't get even half the Millennium full. Plus you'd have extra seating on the pitch.
I would love some exhibition games against European teams though; we'd be murdered but wouldn't you love to see the Devils play Eisbaeren Berlin? Better than pre-season warm-ups against teams you're about to play 6 times over the course of the league season.