Um, yeah, as Micah said...he was being sarcastic.....
As far as Scion goes, think market share (basically the same reasons the Japanese luxury market exploded here in the 'States in the mid-eighties - OK, it took some time for it to "explode"). The Scion is similar to Saturn for GM (if that's a similar example).
They get to try out different manufacturing techniques, other designs, price-points, etc. without "messing" with the Toyota name directly. When Saturn first came out, lots of people (and I'm sure plenty still don't) know that they are a GM division - but just look at the way they market and sell and produce. Almost all other GMs cars have some mention of GM Financing, etc.....with Saturn, it's "Saturn Financing".
Look for Toyota to do the same with Scion - only, much as Toyota does, it'll make it better.