On a side note, is this really going to be considered a "shonen" series? XD It hardly seems that way so far to me! Unless the high school turns out to be a front for something epic! Doubtful, hah.
This could very well be a shonen manga. "Shonen" simply means that the target audience younger males, about 10-18. Beyond that, there don't seem to be any other real "requirements", least of all for being epic, even if a lot of shonen has that tendency.
On that note, I'd argue that this series very much has the potential to be epic in its own way. Clearly, you can't say much from a first chapter, but it looks like Hachiken's got some sort of inner struggle going about his dreams, and he's going to have to overcome/somehow deal with that. This, in fact, was a lot of what made FMA so epic for me. Also, it looks like it's going to be pretty hilarious as Hachiken tries (and, I'm going to guess, succeeds to some degree) to adjust to the culture of the school.
Really, when all's said and done, does it matter that much if it's shonen or shojo or seinen or josei, or if it's not the common contemporary definition of epic? I'd wager that Arakawa doesn't draw because it's shonen or because it's epic, but that what she draws what she wants to, and that (mostly, at least--I'm no aficionado of her works!) happens to be labeled shonen. (And epic, I think.) I can speak only for myself, but I'll read it as long as I like it, shonen or otherwise.