Personally, I think this was just Taker screwing around with Brock Lesnar, with the fans, and with the IWC. This match will never happen, especially if Lesnar is planning to continue his MMA career. Vince won't be pissed off about it, a little free publicity for the WWE to its targer demographic.
At most, this could , I guess, lead to a Batista/Taker feud. Batista has been talking the talk regarding MMA, but has not followed through and likely won't. A returning Batista could challenge Taker, saying that Taker disrespected the MMA world by calling out their former champion in the heat of the moment. Other than something like this, I think the interaction meant nothing whatsoever.