I can't find any opinions on this. Since we began linking to our FB page, our rankings have dropped significantly. A #1 spot for 4 years, dropped to #12. Obviously, many factors could have caused this, but we haven't made any changes to the site. My gut tells me that linking to the FB page has caused a subtle drop in our PageRank, enough to affect our rankings.
All things equal, would you guys expect a negative impact from linking out to the FB page? I see very few sites in the top 20 in my industry who link to FB. I am just looking at this from the standpoint of outlinking. I have always believed that linking to quality external sources have a positive user/SEO benefit. But am not so sure about linking to your FB page, which reciprocates links back to your site. I'm starting to think there is very little benefit to doing this.