Granted, this is a little biased b/c I just bought the ML350, and I will agree that the new X5 looks much better than expected however, when I compared the two, several things stood out to favor the ML...

Base price of ML is more than $3K cheaper
Interior of ML looks MUCH nicer IMO (X5 looks VERY plain)
ML350 is faster than the new X5 3.0
Exterior is a toss up as both look very sporty

I feel the areas that will make the X5 more attractive is simply the 3rd row seat but this looks very cramped but I wish my ML had this. Also, I'm interested to hear how the ride is. I got my ML with Airmatic Suspension and this thing rides like you're floating on clouds! VERY SMOOOOTH. If the new X5 can accomplish this, then I think it's very good competition for the ML but to say it will "easily outpace the ML" is a little presumptuous.

Don't get me wrong...I really like what I've seen so far about the new X5 and I'm interested to see how others feel about it after owning it.