Something you guys should consider about the riddle leak. It suffers from the same problem that many of those "this is what everyone is bringing to E3" leaks have, namely that there is nobody who would ever have access to this information all at once.
It is important to remember that E3 is not necessarily cobbled together in an organized manner. Sony, Microsoft, and Nintendo do not work together in order to put together a good show. Nor do these companies need to register any content with the ESA in order to determine what can and can't be shown. It is a trade show that has been co-opted into a giant piece of targeted marketing shlup (e3 used to be targeted toward investors, now it is for whomever has an internet connection and a few spare hours).
The big problem with this leak is that it implies that the leaker had extremely intimate knowledge of not just the bits on the showroom floor, but Microsoft and Sony's independent press conferences as well. The press conferences you all watched yesterday are technically not part of the trade show that ESA puts together, and there is virtually nobody that would have this kind of information about more than one of them before the fact. These conferences do not even happen in the convention center. They happen in theaters in and around LA and are run solely by the companies that host them.
You could make the case that the leaker is reporting based on observations on showroom setup, and the timing of when it first hit the web might possibly coincide with when that might begin, but you have to then limit your interpretations of the riddles to details observable on the floor itself. This means specific details revealed in trailers shown only at the pressers are unlikely to be relevant to the leak. But then again you have to consider who exactly would have access to this information?
That said, anything that looks complete enough to have a playable demo in those pressers is absolutely fair game to be on the floor. So if this is legit you might be able to narrow your riddle answering by a bit just by looking only at games with observable gameplay.