This is something that can't be overstated. OK, yeah, I'm biased; I know and have worked alongside several of the folks at EveryBlock, but I doubt you're going to find a better group of designers/developers available for building this sort of service.

Sure, the code's open source, but it only exists at all because these guys have been in the trenches for years, wrangling things that can take years off your life and turning some of the crappiest, gnarliest data sources in the world into useful, well-designed data-browsing interfaces. Access to that sort of concentrated experience/expertise is worth quite a bit of money all by itself, never mind the other stuff MSNBC gets out of this deal.