After doing a quick bit of research, I have a theoretical theory. According to Wikipedia:
We must be going through the WAP APN, from which all traffic from BB Messenger and Emails goes. The Web/Internet APN must be the one being metered by the provider. If this holds true, then yes, theoretically, if Opera can use the WAP APN, it shows just like mail/IM traffic and so is unmetered/unlimited. Hopefully if it is, hooray for Opera!
