Vantagepoint (and nothing else, for that matter) can 100%predict a legitimate crossing of a moving average (as many illegitimate crossings will kill you). However, when looking at the software, you'll notice that the averages in Vantagepoint cross one or more days prior to many legitimate crossings of regular MAs of the same length.
Furthermore, with moving averages in general, you can't just buy when the fast MA crosses above the slow MA and vice versa. However, using either another indicator for confirmation, or a violation of immediate support/resistance, one can profit well from MAs, especially from predicted MAs, such as those in Vantagepoint, as you would gain an early entry into a trending market.
I've been happy with the predicted MAs in Vantagepoint, just NOT with the hype surrounding the prediction of "next day" highs and lows. I'm glad to see, from a prior post, that I'm not the only one with this dissatisfaction. However, by using the predicted MAs with an intelligent entry strategy AND trading a number of markets, I'm convinced one could make a nice chunk of change overt the long haul..
Happy trading.
-Lizard