I am certain that Aguero would prefer a move to Real M - Think about it - besides all the rumors/facts that all his family live in Madrid, he just bought a new house (rumor), and he is adapted to live in Madrid/Spain - Aguero is currently playing with Argentina national team. Regardless of how bad they play, he forms even stronger bonds to his national teammates. Do Juve have any Argentinians? Do Real M?
Given all those facts (and rumors), I am certain that Aguero and his agent are flirting with Real M and he prefers to go there - even if he will be hated by the Atletico fans.
SOOO.. It all comes down to if Real Madrid are making a bid within the next weeks - maybe even months! BUT I think that Marotta is smart enough to know that we cant afford to waste time, if Aguero are waiting too long because he want Real M to make a bid. THEREFORE: When Argentina finishes in Coppa, we will know for final, if Aguero will come or not, within 1-2 weeks, and NOT before. Lets just pray that Argentina will loose or draw to Costa Rica. This "not-knowing" is nerve-wrecking.
Personally, I think there is only 25-50 % chance that Real will make a bit = Aguero moving there, BUT I am only 75% certain that he would move to Juve EVEN if it is Juve or to stay at Atletico, which means that overall, its 50/50 :-S
(I am 95 % sure that he won´t move to England)
Extra: taking the recent comments from Marotta into account, I think he is already looking for an alternative (Rossi), because he knows that it is only 50/50 with Aguero.