1. Make sure you see the Falls from the Canadian side also, it has the better view (meaning the stuff is actually on the US side).
2. Historic stuff near the Falls you probably should go to Niagara-on-the-Lake
. Shaw Festival, buildings, etc.
3. May be get some ice wine while you are at NotL
4. London, ON may have some places to visit.
5. Agreed with above: between London and Windsor is a whole lot of nothing. 401 is straight and mostly flat, try not to fall asleep.
is the largest city between London and Windsor. Just read about the Underground Railroad thing on wikipedia so that may be interesting. The one thing I remember is once you see the Chatham sign on 401, try not to speed too much as the OPP seems to need $ there.
7. Before reaching Windsor, you may stop by Leamington
and try some tomotoes. Not sure if you can bring them over though.
8. There are a few historical sites to visit in Windsor, but if short on time I would just focus on the bridge/tunnel and take a picture of the Detroit skyline on the riverside. Zooming in on the Joe Louis Arena sign was a decent test of your camera equipment. Day vs night can be different as well. If you choose to cross over the Ambassador bridge, be prepared to wait along Huron Church Road (consistently voted as one of the worst roads in the province, road conditions wise). There may be a few "open solicitations" on rooftops/roadsides along the road aimed at the bored truckers.
Should you decide to make a detour to Toronto, that's a whole different game. Let us know and we can give more relevant info. Will there be kids?