Here is the text of the FCC press release about new rules for faster number transfers between carriers.
Interesting. My girlfriend ported one of her two Sprint lines to Cox's "digital phone" service this month and the transfer took 11 business days. She called to port the number May 2 and it was completed on May 17.
I have no idea what's involved with it, but I ported a number from Sprint to tmobile last Thursday and it only took a few hours. I would have lost my mind if it took days.