All the reasons @Chopper3 gave are still valid ones:

• The actual authentication process is secured over SSL/TLS.
  (at least if your OpenID provider isn't made of suck)

• Everything else you do on ServerFault is public^*

• Adding SSL to StackExchange sites is computationally expensive
  (Good enterprise SSL accelerators range in cost from about as much as a pony to about as much as a house!)

^* – Possible Exception: Associating email addresses with your account & subscribing/unsubscribing to site newsletters.
I agree that these things should probably be happening over SSL if they aren't already.

All the reasons @Chopper3 gave are still valid ones:

• The actual authentication process is secured over SSL/TLS.
  (at least if your OpenID provider isn't made of suck)

• Everything else you do on ServerFault is public^*

• Adding SSL to StackExchange sites is computationally expensive
  (Good enterprise SSL accelerators range in cost from about as much as a pony to about as much as a house!)

^* – Possible Exception: Associating email addresses with your account & subscribing/unsubscribing to site newsletters.
I agree that these things should probably be happening over SSL if they aren't already.