Spf

How widely deployed is SPF as of October 2013?

root@weasel:/var/log# grep -i spf mail.log | awk '{print $6}' | sort | uniq -c 
     33 Neutral;
    567 None;
    758 Pass;
      4 Softfail;
      4 Temperror;
      7 warning:

Too bad Yahoo DNS service doesn't allow for the creation of TXT records: https://support.google.com/a/answer/172167?hl=en