We just did a 14 day cruisetour and we each brought 1 pair of dress shoes, 1 pair of sneakers, and 1 pair of sturdy NuBalance walking/hiking sneakers. We were able to get along just fine with that (although it must be a record for my wife!). We wore the dress shoes only at dinner, and lived in the sneakers the rest of the time. Unless you're planning on doing some serious hiking, I don't think hiking boots are really necessary.
I have never taken hiking boots, but I don't hike more than 4 miles at a time. I take 2 pair of walking shoes. Perhaps if you disclose where you are hiking, more information could be given for that particular area?
Just for your information, in Juneau. my sister in law was turned away from a hiking trail by a guide because she did not have hiking boots, water or a jacket. She and my brother in law were guided back to the start of the trail by this guide with a lecture on safetly while hiking. If you are serious hikers, dress for the part, if not, leave the big stuff to the professionals. We heard of people being chased by bears (it has something to do with the smell you exert after eating red meat). We were surprised at the powerful feeling of being really alone when on the trails. Above all, be careful and know what to do if a bear follows you. It is not as unrealistic as it seems.
My boyfriend and I did a hike on the Preserverance Trail in Juneau. The last portion of the hike was fairly steep, and if you are worried about ankle support, hiking boots would be good. We both wore tennis shoes and were fine (we do a lot of hiking and I wear both hiking boots and tennis shoes). We went with Gastineau Guiding and they provided a day pack with water, a snack, and a rain poncho and our guide, Becky, was super. I think if you don't plan on doing any kind of hiking, comfortable walking shoes are all you need.