Back in April, we covered Internet telephony startup Ribbit's integration with Salesforce.com's on-demand customer relationship management applications. There, we covered Ribbit's open APIs for delivering services such as making and receiving calls in on-demand applications, recording and saving messages and more. Now, as our parent site GigaOm is reporting, BT (British Telecom) is buying Ribbit for $105 million. Will BT protect Ribbit's openness?