First of all, if you don't really have a handle on how the GPL works, go and read this guide. It is well written and informative. I thought I knew how things worked. I was wrong.
One of the key clauses in the GPL v2 is the 4th clause:
You may not copy, modify, sublicense, or distribute the Program except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.(emphasis mine)
From the guide:
If you have redistributed an application under GPLv29, but have violated the terms of GPLv2, you must request a reinstatement of rights from the copyright holders before making further distributions, or else cease distribution and modification of the software forever. Different copyright holders condition reinstatement upon different requirements, and these requirements can be (and often are) wholly independent of the GPL. The terms of your reinstatement will depend upon what you negotiate with the copyright holder of the GPL’d program.
Since your rights under GPLv2 terminate automatically upon your initial violation, all subsequent distributions are violations and infringements of copyright. Therefore, even if you resolve a violation on your own, you must still seek a reinstatement of rights from the copyright holders whose licenses you violated, lest you remain liable for infringement for even compliant distributions made subsequent to the initial violation.
To put this into context, the maximum exposure per document for copyright infringement is $150,000.
Additionally, in the news, there are many instances of companies who are in violation of the GPL and get sued, and eventually return to compliance and continue to distribute GPL'd programs later on (in compliance) without having gone to all of the copyright holders.
My guess is that this trend will only accelerate. Looking at cloud computing, almost all of the infrastructure is built on top of open source technology. Much of it is GPL v2 only. The same thing is true for netbooks - most of them started out as Linux only and have only belatedly added Windows XP as an option for users.
The reason for this seems to be quite clear. Open Source has accreted enough mass to become a major force in the industry. It allows smaller companies to leverage man-centuries of work to rapidly deploy products with extremely flexible licensing. This trend is only likely to accelerate as the pace of technological change increases.
The elephant in the room is the termination clause in the GPL v2. If the current trend continues, more and more companies will break the GPL v2 without truly understanding the ramifications of their actions, return to compliance and continue distribution. This will start to create a massive overhang of liability over those companies - $150,000 per copy distributed starts to add up very quickly. Although it is doubtful that many traditional open source copyright holders would exercise their rights and sue violators, the trend of some companies hiring people to work on open source (particularly at Google with their 20% time) would allow for a less traditional, but highly effective form of corporate warfare to emerge - particularly once the market has become saturated with violators.
If my prediction is correct, I would expect to see increased corporate sponsorship of open source participation on company time, particularly on code bases that are strategically positioned to affect industries relevant to said companies, essentially, infrastructure code like operating systems, programming languages, web/application servers, library development, etc.
