How do I move the Preview sidebar to the right?

Not possible, I'm afraid.

quite agree. I think Apple have dropped the ball with Preview. Sidebar on the left is uncomfortable, merging pdf's is no longer intuitive, no ability to make default view with thumbnails - all makes for a less impressive app

File a bug reportwith Apple for lost functionality.

Mark my words- we are unfortunately witnessing the beginning of the end of Apple. They have run out of ideas and their software no longer makes sense. Final Cut Pro X is one of the worst programs ever invented since Windows ME and Preview is another disaster. Their big announcement for the new iPhone?...that's right...a finger print scanner. A finger print scanner...really? Nice work, guys. Sorry to see you go.

This response is decidedly late to the party but I couldn't resist!

Apple isn't perfect and this seemingly annoying feature of having the sidebar appear on the left-hand side in Preview is a pain in the arse but I'd say overall that when I've looked at other options on the market, no other company comes close to offering a complete solution to my needs. I'm no Apple apologist but am simply pointing out that the "Apple is doomed" mantra spouted by the same old people is getting tiresome having heard the same thing for the past 6 years. I wholeheartedly agree with letting Apple know when they're crap on these forums and what features they need to create or what existing features they need to improve upon. But using isolated incidents of pockets of fallibility as a clarion call to announce the death of the company is short-sighted and ignorant to what the company is able to consistently get right.

Yes, what? I was watching the tutorial videos on Lion 7.5 on MacProVideo and his Preview Sidebar was on the right !