said by FFH:Tis funny you mentioned that. 5 years ago when I was running TKIP routers, I switched the key interval to 300 seconds. It wasn't adversely performance, so I figured "why not?".
Even if you are using WPA/TKIP, you can still better your odds by changing the "Key Renewal interval" in the wireless router from the usually default 3600 secs(60 mins) down to say 600 secs(10 mins). That should bring it under the time needed to crack the key. By the time they crack the key, it would already be changed.