I had to come out to California on business this week. Last night, I took the opportunity to go into the San Jose Chevy dealership to inquire about the Volt. They have seen three total. One came in a couple of weeks ago, and sold in an hour for $10k over list. Two more came in Wednesday morning, and both sold by Thursday afternoon at $8k over list to a business owner who had come in from out of town and was on his third different city trying to buy Volts. I got to sit in those two, but not test drive them.
So, based on this one data point, it's not exactly impossible to buy a Volt at present, but it's certainly not easy. It's not like they are back-ordered for months, but you'd probably have to sit in a major urban area where they are available, make friends with all the dealerships, and then be ready to pay well over list when one showed up.
This particular dealership said they had only 40 allocated to them for all of 2011. So it could be a while till things settle down.