Personally, I feel the answer really depends...
On the type of union.
I have large union with a small part of a company total sabatage / break a deal agreed by 90% of the other union associates. Why -- all political. They had no concern for the 100's of unionized workers at the company. They were more concerned about making a point. The company went out of business and 1000's lost their job for the sake of about 30 odd associates belonging to the one union.
Or a union may actually do some good where they actual do work on behalf of their members but understand the limits on the business side.
On the global economy
Way back when, unionization made a lot sense. At least to me after reading my history books. Big business exploited workers and created very unsafe working conditions. the few got very rich at the expense of extreme hardship by the many, and even resulted in the loss of life of some of the workers.
With globalization and leveraged services, the transition will be painful for many of us in IT. We were protected by regionalization. But now servers can be managed from across the ocean. Even easier to outsource software development in many situations. We all know why -- labour costs are far cheaper in South East and East Asia than in USA or the UK.
These new "resources" will make more money which will stimulate their economy and increase the demands for a better standard of living.
Hmmm... This looks very familiar to what the developed world went through. I suspect many workers will demand safer working conditions and more money. The only way they may be able to do this is with the power of Unions. This will most likely require changes in regional legislation. So perhaps history may repeat itself.
The big mystery here will be China. From what I have heard, their standard of living is improving, Tiawan still has not been "absorbed", but past history really suggests that it will be a real struggle to allow unions. This may be perceived as ironic since China is considered a communistic / socialistic country, and unionization is often considered a "left" socialistic concept.
On the local economy
To me, it seems that big business and politics is moving to the "right". Before, benefits used to be a "selling" feature to work for a company -- on-site daycare, top-up pension and stock options, etc. Now, I see a reduction in benefits, no nice bonuses and raises seem to be slim.
Part of this is from the recent recession and the burst of the tech bubble, and the other part is due to outsourcing to off-shore resources. (I am sure the looming debt of the USA is also a concern to many.)
But business and government still seems more brutal seems to be shifting to the "right" -- rulings in favour of business, less environmental restrictions, etc. This may result in another battle between business and workers.
Personal Ethics of the CEO's
We have all seen the greed of the corporate world - Enron, MCI, Nortel, Black. It absolutely amazes me how much senior management "earn". Some of these guys work hard and know their stuff. But others are weak or make poor decisions or seem much more interested their very fat bank accounts than the growth of their company. I guesstimate that earnings for senior management could pay the wages of 500 or 1000+ employees. Does each of these VIP's actually do the work of 500 or 1000+ employees???
Moreover, as per recent legal rulings, some of these the big decision makers make decisions based on personal gain / conflict of interest. This seems to me to be lousy for the company and most of the workers.
What this leads to is frustration and anger. And if pushed far enough, anger and frustration can lead to major mass mobilization, and perhaps unionization of sectors that are currently not unionized.
Personally
I have worked in a Union -- it never helped me. I never had to work on a "line" but I feel this would have been a job I would have hated. And paying union dues is/was painful.
I have worked within a Union environment -- problematic, and really slows things down. I need to do technical jobs but was hindered many times because of a required union activity. Something as simple as climb a ladder.
So I personally feel that unions should be avoided. However, when society demands / requires more equality, a better standard of living, and a safer environment, unionization becomes a necessary action to empower workers.
Yea, I know I ramble.