My first response would be NO, but then I am not a seasoned programmer. Although E-Sword is Free it is not opensource and is owned and developed "primarily" by one guy. You can't easily access his data or create your own modules (Bibles, references etc). THus I don't expect us to be able to read his proprietary format .bbl
On the other hand "The Sword Project" is opensource
and you can create your own modules. You can also use an available program "Diaspora" to extract and convert the modules text to a couple formats. With the text extracted you can convert it to the OSIS format as mentioned above.
However, this raises the question of whether we should consider using the modules from "The Sword Project" directly - both are opensource, and then we wouldn't have to reinvent the wheel or recreate a whole bunch of modules in OSIS format. It also enables new bibles or bible updates created for "The Sword Project" top be directly downloaded and used :?: