As far as I know the two are not related.

The resource credit system will replace the current 'bandwidth' model. Basically the more SP you have the more bandwidth or (after tomorrow 5pm Dutch time) resource credits you can spend.

The voting system itself should still be relatively the same based on stake (with a few tweaks but nothing major).

But in the future this could change (I'm getting ahead of myself) in the form of Account based voting.

Account based voting is a different reward model not based on the amount of Steempower but on the amounts of votes from different accounts you get. This in combination with Oracles (that white lists accounts, so people with a 1000 socket puppet account can't rig the system) could be a more fair system to find 'good' content. This is not part of this hard fork.