@Chris,
OK, you got me there :-) I guess I should have said ...

If the theme you're buying has "SEO" listed in a bullet point list of features with no elaboration, it's probably nothing special. Ask for details!!!

StudioPress themes (as they stand right now, pre-Genesis) are pretty good at SEO. Not great, but pretty good. We've done a considerable amount of work bringing Genesis up to par with other themes that do SEO well.