Well, you can look at it this way:
Vortech supercharger, no intercooler, 9 PSI = around 270-300HP
If you where to take away the parasitic effects of a supercharger, and add an intercooler, one would assume more HP possible. Add ice to the intercooler's supply line, and you should get more power.
The kit will be running around 8PSI base. What you do with it later is up to you. (it does have a wastegate) However, the intercooler only flows around 450cfm which is still good for around 9-10PSI at 5000rpm on a 2.5L
Only a dyno run will reveal the amount of HP gains this kit will make. The car that the first kit is being developed on has already had numerous dyno runs before the turbo.
-Chris