It seems that the Government of India has already issued a strict warning to all telcom players in India [Source: All major new papers dated today] to put in place necessary security systems within 15 days, else stop BlackBerry services. The "necessary systems" would definitely mean systems that would be able to decrypt messages/communication sent from a BlackBerry device.
Well, the implication of a Ban of BlackBerry services would be really huge in India. India currently has over 400,000+ users of BlackBerry services and they would all be affected.
RIM has on it's part clarified that the company operates in more than 130 countries, and that it respects the regulatory requirements of governments. However that it does not comment on confidential regulatory matters or speculation on such matters in any given country.
Well, we need to wait and watch on this rather tricky regulation.