There is an interesting discussion on DrugMonkey about Tenure.
I think that the original comments are making a rather important point. High value research with a short term pay-off is ideally suited to the private sector. They have every advantage in pursuing these goals and lack the "overhead" of an academic institution. I know that discussions of comparative advantage can be complicated but this situation is one where the private sectors really are better poised to solve the questions.
The advantage of the academy is in long term planning and results. This environment gives stability and the ability to pursue dead ends. Even if the academy was better at some short term goals, it's still better to have it focus on the goals where the structure is advantaged relative to the private sector.
One argument against tenure involves the complicated issue of mandatory retirement. I think that this issue is not unique to academia and it is an independent issue from tenure. It is also unclear, in a world where pensions are so unstable, what the options are. Perhaps we need to reconsider ideas like seniority based salaries? I am not sure but I see this as a more general concern and only distantly related to the issue of tenure itself.
But the real issue seems to be whether or not the post-tenure world is good for the academy. I would argue that the answer is no. Perhaps I made a very bad decision to go back into academics at this time given the current pressures but I can't help but think that the levels of deprivation seen by junior academics are dysfunctional. Young Female Scientist talks about the sorts of deprivation that junior academics undergo; after a decade of such lowered standard of living why is it seen as being "lazy or dysfunctional" to want job security?
So I think that there are many good arguments for tenure and I think many of the "anti-tenure" arguments are red herrings.