Wellll, their policy states:
"1.10 Number Transfer on Service Termination
BroadVoice may, solely at the Company's discretion, release any telephone number that was ported in to BroadVoice by you and used in connection with your Service to your new service provider, if such new service provider is able to accept such number, upon your termination of the Service, and provided (i) your account has been terminated; (ii) your BroadVoice account is completely current including payment for all charges and disconnect fees; and (iii) you request the transfer upon terminating your account. BroadVoice will not transfer or release telephone numbers that it has assigned for use in conjunction with your Service."
The scary part is "may, solely at the Company's discretion." Which means if they like the number you ported in to them, they can keep it for themselves. Or just never get around to porting it out, etc. Unlike the wireless co's, they are under no legal nor contractual obligation to recognize your ownership of the number once you port it to them. It's theirs. Take a look at this poor fellow's experience:
http://voxilla.com/PNphpBB2-viewtopic-t-6569.html