"A DAC is a database lifecycle management and productivity tool that enables declarative database development to simplify deployment and management. A developer can author a database in SQL Server Data Tool database project and then build the database into a DACPAC for handoff to a DBA"
You: Hey, that sounds familiar. How is that different from Visual Studio 2010 Database Edition aka DataDude aka GDR aka VSDBCMD.exe?
Microsoft: They're, like, totally different ok.
You: How so?
Microsoft: Well they just are. DACPACs replace all that GDR stuff. That was just crazy stuff the Visual Studio guys came up with you know. This is the real deal from the SQL product team. And we can package data too, in BACPACs.
You: Awesome. So this'll solve that problem about also upgrading reference data when I push out a new version of the schema?
Microsoft: Oh no. BACPACs can't be used to upgrade an existing database instance. Just to load data into new databases. They're for moving databases between servers.
You: Like a backup
Microsoft: Exactly like a backup, yes.
You: ...so... can't you just use a backup?
Microsoft: No. DACPACs and BACPACs don't just contain the database. They encapsulate the whole data tier application, so they include other items you'd need to deploy, like logins.
You: Cool. And agent jobs as well I guess?
Microsoft: Oh no. Just logins and ... well logins anyway. Try doing that with GDR. And you wouldn't be using sql_variant anyway would you? No.
You: Come again?
Microsoft: Oh nothing.
The author notes this conversation was imaginary, and any resemblance to reality is entirely coincidental