Is it possible to reorder spaces in Lion?
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.
it seems you've accepted an answer, but here's a workaround:
Turn ON automatic-ordering (System Preferences > Mission Control > Automatically rearrange Spaces)
Command-Tab through applications on each space until you get the order you want (they will automatically reorder themselves.)
Turn OFF automatic-ordering.