Just in time for preparing our RailsConf talk I found out how to copy text with color syntax from TextMate. Simply Ctrl+Alt+Cmd+R in TextMate and paste in Keynote. Of course you need the copy-as-rtf-tmbundle from Max Muermann. I was using XCode for that before, but the keyword detection was different that Textmate’s which I prefer.
cd ~/Library/Application\ Support/TextMate/Bundles
git clone git://github.com/drnic/copy-as-rtf-tmbundle.git “Copy as RTF.tmbundle”
DrNic put the bundle on github.