Interesting article in the recent Bulletin for Biblical Research: T.B. Williams, ‘Bringing Method to the Madness: Examining the Style of the Longer Ending of Mark’ BBR 20.3 (2010), 397-418.
Basically Williams argues that previous discussions of the style of the Long Ending have been methodologically unsound. So he proposes a sound method and procedure (or methodological procedure), applies this to the evidence (well, half of the evidence), and proposes that the style of the Long Ending is distinctly non-Markan. So no surprises there then.
Interestingly he states: 'due to spatial limitations and the fact that dissimilarity reveals more about authenticity than similarity, our discusson will be confined to strong indications of an un-Markan style plus instances that have wrongly been labelled un-Markan' (p. 404). This looks like dealing with only half the evidence to me.