Yes. Or possibly even a single identity column that was re-seeded each year to yy00000[0]; the "-" could be added prior to display just for the "visual effect" for the user. "SET IDENTITY_INSERT ON" would be needed for prior year, with logic similar to above, but hopefully that would be relatively rare.
SQL DBA,SQL Server MVP(07, 08, 09) A socialist is someone who will give you the shirt off *someone else's* back.