Okay, there's actually a key difference between "getting a Rioter to notice" and "getting a Rioter response". I've talked with a few on occasion and they seem to be pretty on top of their chosen mediums (some choose Reddit, other vBulletin, and yet others CB), but they also (again, from what I've come to understand, I apologize if I'm misinterpreting) are keenly aware of the attention a comment can give a thread. A lot of them are pretty cool people but any footprint they make are like magnets and the consequences of that can be very good or very bad.
For example, an @Ironstylus thread asking about Leona artwork and some sketches would probably get something, because there's no harm in IS showing off some personal sketches and other artwork that's already been done, but an @Ironstylus thread asking about a VU would have to be treated with care because simply having that Rioter fist next to a title like "@Ironstylus next VU?" will get people excited, and some may even be disappointed by a simple "nope, can't say", and he will no doubt be bombarded with replies of "X next X next!".
Usually I find Rioters prefer to jump into already made discussion. So my best suggestion is to ask and address the community, the players, and try to get some good back and forths going. Not only do you get opinions from other people but you also allow Rioters to jump in on the much more specific topics that are created. This post, for example, is a great example. You could have just said titled it "@Rioter, what will it take for you to notice me?" and thus make any comment from a player kinda trivial, but now you have this (and hopefully other) comment(s) that Rioters can confirm/deny/expand/correct