Does anyone know if there is or will be a supercharger for the 4.6l northstar engines??

Someone is making one aftermarket. But I don't think Cadillac is making one..

check out caddyinfo.com, and check out the northstar supercharger project. Sounds like a good deal.

Check this site: http://www.mechtech-ms.com/

There's an article in the Jan 03 Issue of Hot Rod on supercharging the Northstar. They used a Weiand unit on a custom intake. The company specializes in Northstar perf parts.
Cadillac Hot Rod Parts? CRHP.com? Don't exactly remember the website.

Here is the website www.chrfab.com