We did, in 2010, what you are planning to do in 2013. From the time our trans-Atlantic flight landed until we were in the departure gate for the flight to Brussels was no more than one hour. Depending on the direction of your cruise you will be flying to either Brussels or Zurich. When you get to the departure gate there will no doubt be several people there who will be on the ship with you. That is a good time to introduce yourself to them and get to know them a bit before the cruise.
A slightly bigger concern is your luggage, but two hours is more than adequate time to affect the transfer. So I have no doubt you and your luggage will arrive at your final air destination together. I assume you are flying on BA, but whatever airline, the agent checking your luggage should (and probably will) check your connection time and if it is under some prescribed number of minutes, they will label your luggage "SHORT". That is a signal to the baggage handlers at Heathrow to hurry it up to the connecting plane.