Katy, we actually moved from Buffalo to Alexandria, VA a few years ago. :)
Buffalo is a city with shrinking pains. There are a lot of bad neighborhoods and a high crime rate, and the city is ostentaciously segregated (an older gentleman I knew who was a native Buffalonian once commented that the city "has always been diverse, because we had the Irish, the Italians, the Germans, and the Polish"). I don't know where your husband's job offer is, but if it's within walking distance of Main Street within Buffalo itself you might want to consider getting a house further out within walking distance of the metro. I worked downtown, and there were a few snowstorms where I don't know how I'd have gotten home if it wasn't for the trolley/subway. If you're going to live by Main Street, though, keep to the blocks off the west side of the street rather than the east side; there are many more abandoned properties and higher crime on the eastern side.
Kindergartens are mostly full-time. If you're interested in having more children in a hospital-with-midwife setting, Women's and Children's is a great hospital in Buffalo, and there are midwives who have admission privileges there. One of the best benefits of Buffalo is Delaware Park - a huge park in the middle of the city with some buildings that date back to the PanAmerica Expo held in Buffalo in 1901. The Buffalo Science Museum is also GREAT; even with access to the Smithsonians, I miss that museum.
People in the city sometimes have a kind of band-together attitude that isn't present in northern VA, mostly because of the fact that the city is shrinking and nobody really wants it to die. Because of that, there are a lot of cultural festivals and other activities which are widely attended. A significant number of folks put a lot of investment into being Buffalonians. It's a very walkable and bikable downtown, though there aren't too many businesses left. The central library (and the library system as a whole) are impressive. In addition to Wegmans and the CSAs already mentioned, the area also has a good number of large farmer's markets, including one on Elmwood, which rivals any that I've seen in the Alexandria area. Another nice thing about Buffalo is that there are a lot of day trips available, including to Niagara Falls, Toronto, Letchworth State Park, and a particularly cool, kid-friendly hike to an "eternal flame" behind a waterfall in Chestnut Ridge Park (http://www.nyfalls.com/eternalflame.html).
When I moved to Alexandria, I was struck by how many more people there are everywhere, how much worse the traffic is, how long the lines are, and how difficult it is to get a network of people together. On the other hand, the streets in Alexandria are cleaner and there's a lot more diversity. Reverse those, and you'll probably get a good idea of the cultural shocks you'll find in Buffalo.