It has taken four and a half years for Canon to announce the successor to the 5D Mark III, an eternity given today's much shorter product cycles from competitors like Sony and Panasonic. What does the 5D Mark IV tell us about where Canon and the industry are headed? Who is it for? Should you get one? With guys like Tony Northrup (my favorite imaging blogger) and bud planetMitch over at planet5D having already gone hands-on -- and taking a few pages from other industries and other things happening in ours -- we have a really good idea about the answers.