Is there a [Go to file...]?

Its not quite the same, but this might interest you:

Cmd + alt + J

Opens the project navigator and highlights the search bar, ready to type.

Cmd + shift + J Just opens the project navigator.

Command + Shift + O is now the shortcut to find a file quickly and open it in Xcode 4

Since Xcode 4 (including 5, 6, 7, 8, 9, 10, 11, 12 and 13) it's ⌘ + ⇧ + O