While people are generally aware of the tendentious nature of some infobox entries, there's a related issue that is just creeping into my consciousness. See
http://en.wikipedia.org/wiki/Template:Ahnentafel/doc
for a general idea what this is about - oddly enough Template:Ahnentafel itself doesn't exist, but there are variants listed on that page. These templates usually lurk in "hidden" form at the bottom of pages, giving someone's ancestry going back about four generations. There are really two points here: firstly that it is very easy for there to be unverified information in such tables; and secondly that there is a fair amount of pressure from those generally interested in genealogy and family history for us to host this kind of information, when (it might be argued) family history of most kinds isn't really encyclopedic.
The verifiability thing is more problematic to me right now. If you look at [[Catherine Parr]], for whom as a royal there is some excuse for interest in her antecedents, there is apparently a disagreement about the father of Sir John Fogge, one of her great-grandfathers. There is indeed a reference to a printed source. I think all that means is that it doesn't make Wikipedia look stupid to include such information - it certainly doesn't mean it's beyond dispute. As it happens the Oxford Dictionary of National Biography entry has a different theory about Fogge's father; and I'd be happier following that. One thing is clear enough, which is that discussing this matter in detail on the Catherine Parr page would be off-topic, unless it somehow mattered for her life.
So there are a couple of things going on here. NPOV on genealogical matters cannot be achieved, when you go far enough back, just by citing some reference, because you hit areas where there is a lack of definitive and authoritative references. And there is a bigger picture, which is what to do when genealogy-oriented references clash with professional historians writing on the same matters. I'm with following the historians, but that might be considered a bit snobbish by others.
Charles