I would like to preface my post by stating that I am NOT a big fan of going to a thread as a detractor. I have, however, some extreme hesitations about what shovel Knight could bring to the table.
In all sincerity, he seems like a fantastic character, from a fantastic game. He does not, though, appeared to have anything unique about him as a fighter*, nor nearly enough gravitas to when a fan Service poll. Quite honestly, only characters who would love me more in the wrong way, are all from Fire Emblem. I came to this thread to read the initial post and find some merits and his inclusion, but I cannot help but feel the tunneled hype generated by this character is based on frivolous and irrelevant factoids.
* utilizing a shovel does not make him unique, if it is merely different by the sprite alone. If it is a general bludgeoning object, it, in itself, offers nothing of variety. Variation comes from play style, & I mean this in a general term... Not by minute differences in, say, a sweet spot of a sword tip.