From Intel's software blog: Compare Windows* threads, OpenMP*, Intel® Threading Building Blocks for parallel programming
It is also the matter of style - for me TBB is very C++ like, while I don't like OpenMP pragmas that much (reeks of C a bit, would use it if I had to write in C).
I would also consider the existing knowledge and experience of the team. Learning a new library (especially when it comes to threading/concurrency) does take some time. I think that for now, OpenMP is more widely known and deployed than TBB (but this is just mine opinion).
Yet another factor - but considering most common platforms, probably not an issue - portability. But the license might be an issue.
- TBB incorporates some of nice research originating from academic research, for example recursive data parallel approach.
- There is some work on cache-friendliness, for example.
- Lecture of the Intel blog seems really interesting.
