It's been pretty chilly here this winter. I am more than ready for spring! There's a bunch of icy snow on the ground right now, and it may snow some more this weekend. That being said, I did see a guy pedaling along up the road this evening on my drive home, and I went out myself a few days ago. If you're coming here soon, then you'll definitely want to bring some cold-weather gear and perhaps something to clean the road salt and grime off of your bike. They love their salt trucks here...
Weather aside, Cincy definitely has its fair share of hills, and it has plenty of
really awful drivers. I've not personally had any issues with car traffic along the river, downtown, nor on the east side, but the Clifton/Avondale area can be hairy, as well as anything immediately north of I-275. To be honest, there is definitely some nice riding to be done around here, and any local bike shop can give you plenty of recommendations. You can also check out routes for the area here:
http://gis.oki.org/BikeRouteGuide/ (you'll need to zoom in a couple of times on that map before it shows you anything useful).