There's a full promo/commercial out for Smallville's seventh season that shows a lot more than the micro-teaser version that was out last week. It highlights Clark's "copy" Bizarro more and there's more dialog about the Clark/Lex battle of good vs evil.
Also, the scene from last week's promo showing Kara (aka Supergirl) launching into flight is much better. Previously her takeoff was a lazy, slow, Christopher Reeves type of movement but now they've added their signature "super-speed" effect to it. Looks much better that way.