Check out this article.

In short it’s about 2 alternatives for bzip2 and gzip, that do the same as their counterparts, but actually use multiple cores if available, thus greatly reducing (de)compression time!

IMO the original bzip2 and gzip should support this out of the box.. multi-cored machines are already widespread, and more and more tools ( especially cpu-intensive ones ) should be updated to make use of them.. bzip2 and gzip are 2 apps that would benefit a lot!