It would be nice if SC can automatically replace the TO/CC when
Replying/Replying To All with Names from Address Book if they
exist there.

For example:
     From: it's me <john@spare-nobody.com>
writes to me and I have this entry in my Address Book:
     John Spares <john@spare-nobody.com>
when I REPLY, instead of:
     To: it's me <john@spare-nobody.com>
SC would have:
     To: John Spares <john@spare-nobody.com>

The question that will automatically pop-up is: What about those
email addresses which have multiple entries? I know it is possible
to do that but honestly, I don't think it should be in the first
place. Till Address Book is modified to not include the same address
in multiple-entries, this fix could use the first entry encountered.

For some sanity, this could be a feature that is OFF by default and
could be enabled later by those who want this.

Aside: My thinking says that the function that completes names from
       Address Book depending on the name when tabbing could be used
       for this thing. Of course, I'm too stupid to know for sure. :)