Just worked out the final kinks (hopefully). It's a little odd that the Quick Export tool requires a separate overwrite setting.This drove me nuts at first becuase it was appending my database each time even though I had the geoprocessor object set to overwrite. In case anyone else wants to do something similar, this code takes my XY data from a table and creates/overwrites a table within a personal geodatabase. It would have to be modified considerably for anyone else who wants to use it, but at least this is a starting point.
# Import system modules
print "Importing system modules..."
import sys, string, os, arcgisscripting
# Create the Geoprocessor object
gp = arcgisscripting.create()
# Load required toolboxes...
print "Loading toolboxes..."
gp.AddToolbox("C:/ArcGIS/ArcToolbox/Toolboxes/Data Management Tools.tbx")
# Setting OverWriteOutput to True allows geoprocessing tools to overwrite
# the output if it already exists.
gp.OverWriteOutput = 1
XY_Table = ""
outputDB = '"\\\\ComputerB\\AutoSitesShp\\SitesShp.mdb"'
outputLayer = "SurfaceWater"
inputTable = "\\\\ComputerB\\AutoSitesShp\\sitefile_01.mdb\\SW"
# Process: Make XY Event Layer (SW) ...
print "Making XY Event Layer (SW) ..."
gp.MakeXYEventLayer_management(inputTable, "dec_long_va", "dec_lat_va", outputLayer, "GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]];IsHighPrecision")
# Process: Quick Export (SW)...
print "Processing Quick Export (SW) ..."
Output_Dataset = "GEODATABASE_MDB," + outputDB + ",\"RUNTIME_MACROS,\"\"OVERWRITE_GEODB,yes,TRANSACTION_TYPE,TRANSACTIONS,SIMPLIFY_GEOM,no,X_ORIGIN,0,Y_ORIGIN,0,XY_SCALE,0,HAS_Z_VALUES,auto_detect,Z_ORIGIN,0,Z_SCALE,0,GRID_1,0\"\",META_MACROS,\"\"DestOVERWRITE_GEODB,yes,DestTRANSACTION_TYPE,TRANSACTIONS,DestSIMPLIFY_GEOM,no,DestX_ORIGIN,0,DestY_ORIGIN,0,DestXY_SCALE,0,DestHAS_Z_VALUES,auto_detect,DestZ_ORIGIN,0,DestZ_SCALE,0,DestGRID_1,0\"\",METAFILE,GEODATABASE_MDB,COORDSYS,,__FME_DATASET_IS_SOURCE__,false\""
gp.QuickExport_interop(outputLayer, Output_Dataset)
Thanks again to everyone who posted suggestions!