When taking a database from a relatively un-normalized form and normalizing it, what, if any, changes in resource utilization might one expect?
For example,
I wanted to elaborate on Henrik Opel's #3 bullet point. Development costs might go up, but they don't have to. In fact, normalization of a database should simplify or enable the use of tools like ORMs, Code Generators, Report Writers, etc. These tools can significantly reduce the time spent on the data access layer of your applications and move development on through to adding business value.
You can find a good StackOverflow discussion here about the development aspect of normalized databases. There were many good answers, comments and things to think about.