To be a little more clear, I was considering high current to be 20 or so amps, which is high in comparison to what most variable power supplies output, which is usually limited to 10 amps.
EN0 -- There are lots of situations where low voltage/high current is necessary: quickly charging large capacitors, for driving DC motors, battery chargers, or for driving high power LEDs in parallel (as I'm currently doing) ect. There is also the challenge of designing a high current variable DC supply. While these projects usually require some kind of Buck voltage control with current regulators, I would enjoy both the convenience of a single power supply, and the challenge of the design.
4pyros -- The supplies I have been looking at have almost the same current rating both the 3.3v and both of the 12v rails (but yes, you're right, the 3.3 is a slightly higher current rating), but because the 12 volt rails have a significantly higher power rating, I would rather use them for my variable voltage source.