Scientific Linux really isn't a special-purpose distribution. It's just another Red Hat clone like CentOS. (Some people claim that it's actually a superior alternative to CentOS.)
It's as special as Edubuntu. It may be based on RH (as Edubuntu is based on Ubuntu), but it's prepackaged with lot's of software for scientific usage (the same way Edubuntu is prepackaged with educational software).
It's obvious that some distros are more special-purpose and some of them can easily be configured/converted for everyday usage.
Springdale Linux (previously PUIAS Linux) is another RHEL 6 clone but they do provide a repository that contains some computational maths software. That repository is not installed by default, and can be used with the other RHEL clones.
