After months of searching the net for the song containing the lyrics 'Hey hello, now that you're finally on your own...', I decided to email AT&T Wireless directly. I just received this response:
As a valued customer, your mLife is always our first priority. Thank you for contacting AT&T Wireless regarding the song in the AT&T Wireless mLife commercial. The song you heard the commercial was a melody created especially for this advertisement. The song has no name, and is not available for purchase.
There's never been a better time to have an mLife. Your mLife isn't just wireless, it's wireless reinvented. We invite you to participate in a brief survey about your AT&T Wireless e-mail Customer Service experience. You may use the link below to access the survey.
Thanks for choosing AT&T Wireless. We appreciate your business.
Online Customer Service