I know this post is a bit old but still relevant. Let me pipe in as we had developed a user friendly interface in past AND were using "push" to stick the data in front of providers on a MONTHLY basis that enabled them to modify the data right there in a web UI. We then submitted as an EFIO on their behalf.
I'll augment/disagree with Michael a little here. Incenting the providers to keep their NPI data up to date should be relatively easy....CMS has to use it themselves! If CMS starts using parts of the demographic data (phone, address) for mailings, queries, data on varied CMS operated sites..this will go a long way to this end. Making the NPI itself more widely used will not do that. The NPI is already somewhat widely used and, since the NPI doesn't usually change, that's not what's out of date...it's everything else.
We assumed when this started, that CMS would use some of this demographic info on file for....something at least. Feed it into PECOS? Medicare Compare? The problem isn't technical in nature, it's bureaucracy since the PECOS people want to collect their own data separate from the team upstairs and next door because....well because....