Well I'll talk to you, even though I don't really know what you are looking for.
First thing may be the Club House. Get there early and enjoy the food and cocktails. Some like the spa although we don't bother.
Will you be using the DTCI? I haven't flown from Heathrow but it sounds fun.
There have been a few threads on when to spring the surprise. Again a few like to keep quiet until they get to the Upper Class check in desk but my personal view is to enjoy the excitement as early as possible.
What about packing? Are you going to use up the 3x 32Kg baggage allowance per person. Even if you only take two cases each I'd have thought it fair to let people know they can pack plenty of clothes.
Seat choice: Again loads of threads about which are the best seats on each aircraft. It will depend a bit on the make up of you group. Seatguru gives some good pointers.
http://www.seatguru.com/findseatmap/findseatmap.phpThat's about all I can think of at the moment, but I'm sure others will come along soon.
Have a great time.
Dick D