- It is highly unlikely that consumers will make a big effort to lobby for the public's interest, and
- It is highly likely that the parties representing the copyright holders will expend enormous efforts and money to try and strengthen/extend/etc. copyrights.
The public is large, poorly organized and difficult to motivate to make a stand on copyrights. Essentially the problem is that changing copyrights don't fundamentally change the lives of most people. For the general public this is a problem somewhat similar to the Tragedy of the Commons, in that the common man doesn't really benefit much from his own efforts, but rather from the collective efforts of all common men, which is only marginally reduced by him being lazy and not doing anything. Unfortunately, this is true of all common men and the result is a tendency to be apathetic.
For the copyright holders, the situation is reversed. There is a relatively small set of major copyright holders, they are well organized and well funded. With the clock ticking on their valuable assets, they are highly motivated to attempt to squeeze more out of the system, and their own efforts are likely to change their own bottom line. They stand to gain (or better said, not lose) vast amounts of money when copyright terms are extended, and are therefore willing to spend lots on lobbying, public relations and other activities to influence politicians.
In the middle we have the copyright extension opponents only hope: the various public and private organizations. They, unfortunately, tend to be underfunded compared to the copyright holders. Their task is to motivate the public, to donate money or lobby their politicians. Most of the public, as previously stated, are not really bothered by copyrights.
The more likely scenario, in my opinion, is that industry lobbying will ultimately be successful (perhaps after numerous attempts) and copyright term will become, for practical purposes, unlimited. Draconian laws will probably be implemented for copyright infringers. However, most of the public won't really care and will continue to illegally share films, music and other copyright content. The legal system will not make (in fact, will not be able to make) a sufficient effort to combat the problem, as the politicians probably don't think they will have to keep their promises to the industry in the long-term. There may also be a backlash from the judicial system and the public about the appropriateness of the effort and money spent on copyright infringers vs. other priorities.
The result will be, more or less, the mess we currently have.
There is an extremely small chance that there will be a small number of content providers who get it and realize that a new business model is required that is not based on trying to to maintain a legal lock on content. If they get enough of a foothold in the market, which will require overpowering the powerful Hollywood cartels (e.g. TV, movie and music distribution), this could a massive shift in the way content is marketed. This is more likely to happen in the book industry, as there less of a lock on the distribution channels, and we are seeming a gradual increase in self-publishing.