I was having the same dilemma. I couldn't decide whether to go ahead an order a 2011 or wait for a 2012. From what the people on the Chevy website, the 2012 Equinox's go into production on 7/18/2011. I also think I read somewhere online that they began excepting 2012 orders (meaning that 2011's couldn't be ordered) on 4/18/2011, but I'm not totally sure about that. With all that being said, I went ahead and ordered a 2011 because one of our cars had to be replaced. I wanted the new Nav./Infotainment system that's being rolled out on the 2012's, but I just couldn't wait.
Also, If you go to
http://www.gminsidenews.com/forums/f13/meet-your-2012-chevrolet-truck-lineup-102251/ and scroll to the Equinox section it shows the updates to the 2012's. They're also going to have an available "Forward collision alert" and "lane departure warning." and some color changes.
However, as the 2011 start to sit longer on the lot, you're more likely to get a better deal on one.