Typo - missing '\' in 1st pathname... I think F:Replicated Data should be F:\Replicated Data, provided you have both the given sde connection file and the gdb at that root directory.You've probably seen that by now, and this is a case where using 'join' from 'os.path' would be useful in avoiding such an error, as in something like this:
import arcpy, os
from arcpy import env
root = r"F:\Replicated Data"
for workspace in ["Auto_Extract_Connection.sde", "Gatekeeper_Extract.gdb"]:
env.workspace = os.path.join(root, workspace)
datasetList = arcpy.ListDatasets()
print workspace, datasetList
...or, could even use ListWorkspaces, I think (I didn't test this)-
import arcpy, os
from arcpy import env
root = env.workspace = r"F:\Replicated Data"
workspaces = arcpy.ListWorkspaces()
for workspace in workspaces:
env.workspace = workspace
datasetList = arcpy.ListDatasets()
print workspace, datasetList