We will be arriving in Zurich early in the AM and have several hours before meeting the transportation to our Rhine River cruise. Any suggestions what we can do and easily return to the airport to meet our contact?
Deposit your luggage at the Luggage Storage Counter in Zurich Airport:
Take the train from ZUrich AIrport to Zurich Main Station (Zurich HB). From there you can wander down the Bahnhofstrasse all the way to the lake. and take in the sites. If you happen to arrive on a Saturday morning there will be a huge flea market set up next to the lake. You can also stroll the Alstadt and take in the Grossmunster Church or the see the famous Chagall stained glass windows at the Fraumunster Church. Look here for a more detailed list of possibilities in Zurich:
I think you should be more concerned that your flight is not delayed for hours or even a day which is not uncommon these days. If you had arrived a day earlier you could have spent a leisurely day in and around Zurich and then ventured of to your cruise the next day.