I would expect 'Mission Control' to allow me to drag spaces in a certain order (with the exception of the 'Dashboard' space), but this does not seem like an option.
This would be especially useful when re-ordering full-screen apps: for example, opening iCal and then opening Mail fullscreen would result in Mail being 'spaced' after iCal. But what if I'd want Mail to have a higher 'priority', thus wanting it spaced before iCal?
Is there an option to re-order spaces without recreating them entirely?
Best Answer
OS X 10.7.2 Update
Since OS X 10.7.2 Desktops (or Spaces) and full screen apps can be reordered, i.e. spaces can be mixed with full screen apps in any order a user may fancy, but with one exception - Dashboard and Desktop 1 (1st Space) cannot be moved.
Pre OS X 1.7.2 answer:
Based on several reviews and reports you cannot.
Seems like an oversight to me as I consider it as a must-have feature.
Be aware there's also something called automatic-ordering (System Preferences > Mission Control > Automatically rearrange Spaces), which apparently orders them based on usage.