It's rather late now, though, considering it's been around for years now without anyone knowing exactly because they did not include that copyright notice.

I have no idea what copyright law says about damages in a case where the infringing party tries to keep their large-scale infringement secret.

The statutory damages option discussed above does not require a showing of actualy damages. It's just x dollars times the number of instances of infringement. Also, while delay in providing notice of infringement can work against the copyright owner, in this case, because Intel is a sophisticated party (i.e., big company with many in house lawyers and outside law firms advising them), the delay in making a claim would likely not help Intel's case.