I use Biblioscape now, but am considering switching to Zotero because I'll almost always take a free, open-source solution over a commercial, proprietary one. Anyway, I'd love to see importing of Biblioscape Tagged Files implemented. This would go a long way toward making my (and others' to come, I'm sure) transition easier!
Choose the references you'd like to export.
Select the destination directory and file name.
I had success with RIS format. It's possible BibTex may work better for you.
Click the gear icon, >Import...
Select the file you'd like to import.
The file will show up as a folder with a timestamp on it. You can rename it, leave it alone, or just leave the references in My Library. Good luck.