@jeffvogelsang
Well, on PFBLOCKERNG/DNSBL page, there is the TOP 1M WHITELIST. You can choose the Cisco or Alexa list and then choose how many down the list from the top you want to whitelist. Then choose what is to be included in TLD whitelist. I see it as a safety net to catch popular domains that could end up as a false positive in the blacklists. I set mine to the top 2k.
A real pre-packaged 'whitelist' like the blacklists would be very hard to maintain and would obviously need to be very large to really be useful. Consider that for it to have value, you would have to decide what to do with sites that are not on the whitelist. Do you block them? If you don't then what is the point of the whitelist? Thinking someone can figure out, for all the blacklists out there, what the false positives are and then making a whitelist for them and keeping it up to date would be about as daunting. Think about the maintenance involved, ouch.
I rarely have issues where I have to add anything to the whitelist anymore, my list is about 45 domains and some TLD exclusions that have been added over the last couple of years. If I test out a a list and see a large amount of false positives I dump it and use something else.
