The xA and the xB are actually based on the Toyota Echo, and serve to replace it as Toyota's main compact youth-targeted offerings. The comment above regarding failed demographics is absolutely false. According to articles I've read, it is now has the youngest average age buyer (35) in the entire automobile industry, replacing VW (38). The brand has also tripled sales projections in its first year in California. The tC is a less controversial, more sales volume based car that will launch nationally in June. It is based on the European Toyota Avensis sedan, but is a two-door coupe.
One thing that is unquestionable in Scions is their value. There is no other brand that offers the low price, eye-catching (whether from attraction or revulsion) design and sterling quality that Scion does. By the way, the materials used in Scions, like the sound-deadening materials, were borrowed from the Lexus parts bin. No one can honestly say that Lexus' materials aren't among the best in the industry.
People who dislike Scions remind me of those who dislike Macs... they can't seem to see past an entrenched design philosophy and interface so they condemn an entire brand.