This bug is marked as Major because it "hits the screen" in GeoServer.
(It is not a showstopper as GeoServer has protected itself during loading)
GeoServer recently ran into a problem when the oracle DataStore recognized a Map provided to the canProcess function - even though the required oracle drivers were not in the classpath.
This allowed the GeoServer user to set up a DataStore that appeared to work correctly up until it was actually used.
oracle module bug:
The oracle DataStore canProcess(Map) method should return false if the required JDBC Driver is unavailable at runtime.
data module request:
It would be even better if the OracleDataStore did not appear in the list of available DataStores returned by DataStoreFinder.