Code Complete covers a lot of timeless concepts such as:
- strong cohesion
- loose coupling
- good routine names
- defensive programming
- self-documenting code
- software reviews
- unit testing
which are certainly relevant today.
Some of the concepts championed in CC are now syntactically enforced in newer languages, for instance C# doesn't allow variable in sub-scopes to be defined in a manner that hides a super-scoped definition.
Other concepts, such as Hungarian notation for variable names have fallen by the wayside in mainstream programming (although anyone still working with the Win32 API will argue vehemently that they are alive and well). Nevertheless, the real concept behind the variable naming convention is to convey necessary meaning and clarify code, concepts that I would argue are also timeless.
All told, from what I can recall (and a quick peek inside my venerable copy of CC), I would say it is certainly worth reviewing.
I don't think, however, that it rises to the truly timeless nature of The Mythical Man Month. MMM address issues of who is doing the work, how and why are they doing it; as well as the costs and complexity of (human) communications. MMM addresses issues which are fundamental to everything we do. CC, in comparison, focuses on practical and pragmatic issues of how we do it. Put another way, if a project is behind schedule, and a manager decides to add 100 people to the team, writing comprehensible code will not really make a difference.
CC doesn't really address significant issues plaguing our industry; but it does provide a good foundation for striving for the best outcome in an often impossible situation.
I would certainly consider them both required reading for anyone who care about software development; and I would recommend re-reading MM whenever you need a refresher. CC is worth rereading if you are leading a development team, setting group standards, or training newer developers; outside of that, I personally find that I long ago internalized the material in CC and practice it on a daily basis.
Hopes that helps. They are certainly two of my favorites.