The Bureau of Labor Statistics put out a very brief report about union membership. It includes an interesting table of professions represented by unions, and the percentage of folks in those professions who are actually represented. The data is from 2010 and includes 2009.
Just over 36% of public workers are unionized. 6.9% of private workers are unionized. I think there is a fair amount of scapegoating going on in regards to unions. Does there need to be some changes? Probably. Stripping public employee unions of collective bargaining rights is not a change I would support wholeheartedly.
I wonder what folks will do if Governors like Walker in Wisconsin are successful. What happens when you don't have the unions to kick around anymore and things are still tough?