So by extension, do people think a swordmage could hold a greatsword in one hand and use it as an implement? Or two longswords, using the off-hand one as an implement only?
I have wondered that question, and have even asked that question during previous discussions on this subject. As I mentioned earlier, I can't find any rules one way or the other that discuss if a player must use one or two hands to wield an implement, only that you must wield it.