The Teiid Designer install includes an empty jdbcModel.xmi. This model persists the your JDBC Sources and Drivers. The decision to NOT include Drivers was driven (pun) by license requirements. In other words, we couldn't include 3rd party jars (i.e. Data Direct, Sybase, Oracle, etc...).
The result of starting with no Driver information will force you to construct a driver for each of your imported source db types. This can be a bit confusing to first time users in quick-start mode.
But after some thought I'm leaning toward relaxing this a bit and delivering the Driver definitions but NO jars?
This would provide a more practical list of potential source drivers. You would need only provide your own jars.
We already provide a large list of Connectors you can use, provided you provide your own jars, so doing the same for Drivers would make the story consistent.
I like this idea. It's good for consistency with connectors (as you mention) and makes it more obvious what the user needs to do. IMO, the fewer steps required to set up a connection, the better.