For this sample set, the hypothesis (“Early posting garners more votes”) is likely to be false. The “p” value is a measure of the confidence in the correlation. Lower p’s mean that there is less likely to be an error. Statisticians think that a p < 0.05 is a good value (if I recall my stats classes correctly).
Could it be as simple as “early posts are near the top of the page and therefore everybody sees them”?