My buddy is the regional product rep for Makita and was telling me that they've got a new saw out, but I don't remember all the specs. It may have been this one:
Makita 4131 7 - 1/4" Metal Cutting Saw but for some reason I thought it was a 10" blade so I don't know for sure.
Anyway, he said he's done long cuts through 1/2" mild steel as a demonstration. The punchline to the demo is when he puts his tongue on the cut edge to show how little heat is generated. Supposedly the blades last 70x longer than an abrasive blade, so they're considerably cheaper in the long run.