Let me consult with our development team, maybe there is a better way to do that, but just off the top of my head...
You could use a PowerCLI script to export existing notes/annotations into Excel file, create custom attributes for these VMs in this Excel workbook and import them to BV (this process is described in our User Guide starting from page 35).
I have found a sample script that will allow you to retrieve VM notes information, please check it out: http://communities.vmware.com/thread/159167
And here is a whitepaper that should explain you how to map these annotations into custom attributes in details:http://www.veeam.com/vmware-business-vi ... urces.html
(see "Sharing Categorization Data with CMDBs and 3rd Party Applications"
Hope this helps!