This wouldn't help with spam (despite the picture) or generic scams, just phishing. So we'd still get the Nigerian princes, the "male medicine", the R0lllllex and the rest. The only stuff you wouldn't get is stuff telling you to log in to [insert bank/store/social network].
TBH, this will only be half successful. SPF and DKIM lets them do this stuff already (and worrying only *some* banks do it) if and only if the receiving server checks the records *and* the sender marks a hard fail rather than a soft fail (which says "I don't think it is legit, but don't ditch it just in case"). What it will miss out on is bankofarnerica.com and the like - you can still phish with an almost-but-not-quite-identical domain name (and even have a legitimate SSL certificate for it).