Sneak Peek #1 illustrates changes to the Adobe Camera Raw interface, including new sliders and expanded capabilities for the Adjustment Brush and Graduated Filter. This peek also reveals a new appearance for the Photoshop interface---dark to make it "match" the Lightroom interface. (Don't worry if you prefer gray; you can change the appearance to the CS5 version.)
Sneak Peek #4 shows Recompose, a new capability that allows you to modify an object's position within the photograph without having to make a detailed selection, layer and mask. It appears to be related to Photoshop's Patch Tool, but with the ability to create replacement content on the fly.
There are two other video sneak peeks on the Adobe Photoshop channel at YouTube. The other feature I like is background saving (see Sneak Peek #2). You can tell Photoshop to save a large file and it will do this behind the scenes while you work on a different image in the meantime. No reference to how much processor power or RAM might be necessary to make this a reality, though.