I think you can definitely cut that bill by a LARGE percentage.
I was in the same situation... House about 3000 sq ft. Electric bill was through the roof. I've cut my bill by 50% or more, and I really haven't sacrificed much at all.
It is important to take into consideration not only the house itself, but also the humans living in the house... Their habits... The times the house is occupied... etc.
It is important to get the people in the house to be on your team with the concept of saving money \ energy. If they don't go along with it you will fail in reducing your bill. You will have to educate everyone on how to turn off lights, and how to deal with slight differences in their routines \ ways of life.
Heating a house of that size is a costly endeavor with electric heat. While some here might recommend a rocket mass heater, I would personally recommend a free-standing wood stove. I actually built and installed a rocket mass heater in my home, but I later removed the stove (kids needed the room) and I put a free standing wood stove in another room. (http://streetjesus.blogspot.com/2010/12/rocket-mass-heater-project.html
) The rocket stove heated up the room it was in well, but it wasn't quite enough to heat the whole house. It required frequent feeding.
We moved kids into the room where the rocket stove was... No more rocket stove. We installed a free standing wood stove in our den. Man, the heat is just outstanding!! The burn times are great, and it will heat the whole house. (You can run the fans if you have a centralized AC and it will circulate the heat.) I'm lucky because I have a lot of land and free firewood. Here is the link to my wood stove install project (http://streetjesus.blogspot.com/2011/12/heating-with-wood-simply-best.html
). It wasn't until I installed this wood stove that there was happiness in my home in the winter months. When we were running the heat pump we paid through the nose every month... and we were still cold. No more! We stay warm now and our bill is low.
In the winter turn our heat pumps OFF. In the summer we set our thermstats to about 78 and use ceiling fans, or we open in the windows.
Another thing... Use a clothesline if you can. An Electric Dryer is an evil thing.
With an electric bill of 600 bucks a month it would also do you some good to determine where its all going. I recommend going room to room and check out all of your devices. Put them on timers, turn them OFF, or use power saving modes where possible.
Hope this helps. Keep us posted! I look forward to hearing how you are saving!