colduphere

It's your honeymoon. Leave your clothes at home.

Well most of them. Large suitcases are a real pain on a fast paced trip. Pack very lightly.

StCirq

Well, you didn't seem to take much away from this discussion, so go do what you want to do. Not sure why you even asked for help. I hope your future spouse likes RR stations and airports. Good luck.

BKP

London: skip the hoho bus. I know it gets recommended as a way to get an overview of the city and stave off jet lag but I feel like it's a bit of a waste of time. I'd rather explore less bits of the city than wizz past a bunch of sites, or more likely be stuck in traffic staring at the back of another bus. Having said that I have taken one -- in the beginning of November. We sat on top of course and nearly FROZE! If you go, grab a cup of something hot to keep warm.

Have you already bought your Harry Potter tickets? They must be purchased in advance. Unless your die hard fans, I'd give it a miss. It will take up your whole day and leave you with no exploring time (or energy) for the evening. Again, I've done it and it was enjoyable but only as a day trip ( we live here) not as a day in my once in a lifetime trip.

You can always make a quick trip to King Cross and take your photo at platform 9 3/4!

My last bit of advice is to take the pressure off. Yes, go, go, go, see everything and come home exhausted but don't feel like this really is the trip of a your life. You'll come back. We took our trip of a lifetime in 2004 and moved here in 2007. If you love travel, if you love Europe (and I expect you will) you'll find a way to come back.