There's an interesting titbit hidden away in the Law Commission's latest Statement of Intent [PDF]: they're reviewing the OIA:
We have commenced work on two new projects this year that were given to us last year. These are a review of the law relating to trusts and charitable trusts and the Official Information Act 1982.There's no other details, and nothing on the website, but there will apparently be an issues paper sometime in December.
The Law Commission has already reviewed the OIA once, back in 1997, and recommended [PDF] reducing the time limit from 20 to 15 working days. This has not been acted upon. I doubt their view has changed - if anything, the improvements in information technology which led to their recommendation have only grown stronger, meaning it should be reduced even further. So, we may see another recommendation for reduction, which will likewise be ignored by self-interested politicians.