I’ve had enough with the slow Preview application in Lion. After some digging I found this tutorial to downgrade the Preview in Lion to the Snow Leopard version. Basically you need to have a copy of both the Preview.app and /System/Library/PrivateFrameworks/MeshKit.framework from Snow Leopard. If you need to associate the default app to open pdf/png with the downgraded Preview, you have to delete the original Preview.app.
tar -pczf Preview.app.tar.gz /Applications/Preview.app
sudo rm -rf /Applications/Preview.app
Update: after installing OS X updates you need to remove the Preview.app again and put the SL Preview.app to /Applications/ directory.Mac OS X OS PDF Preview