See video:
2006 e53 X5 4.8is front end noise - YouTube
(turn up your headphones)

I had heard this noise that seemed to get progressively more noticeable once the snow melted. I thought it was road noise from my snow tires but when I changed to my summers it sounded more prominent.

The vibration/noise sounds like the front diff. There is no significant feedback at the steering wheel. Its present under access and decell but easier to hear when your foot is off the throttle for obvious reasons.

Any thoughts?