Considering how software is developed during a release cycle (implementation, testing, bug fixing, release) I was thinking that one should be able to see some pattern in the lines of code that are changed in the code base; e.g. towards the end of a project, if the code becomes more stable, one should see that fewer lines of code are modified per unit of time.
For example, one could see that during the first six months of the project, the average was 200 lines of code per day while during the last month it was 50 lines of code per day, and during the last week (just before the product DVD's were shipped), no lines of code were changed at all (code freeze). This is just an example, and different patterns could emerge according to the development process adopted by a particular team.
Anyway, are there any code metrics (any literature on them?) that use the number of modified lines of code per unit of time to measure the stability of a code base? Are they useful to get a feeling if a project is getting somewhere or if it is still far from being ready to release? Are there any tools that can extract this information from a version control system and produce statistics?