Well in my opinion the easiest thing you can do is replace the upper intake manifold (or at least take it off and inspect it). I recently replaced my upper intake as proactive maintenance -- I didn't want to deal with any problems down the road. Come to find out the original part was doing OK after 117k, but I put a revised aftermarket intake on there (which has reinforced areas to prevent this type of thing from happening) and I think I'll be fine for the life of the car.
Dorman and Motormite (same company, different brands) both make aftermarket upper intakes for this engine. I believe its about $150 for a replacement. Its a afternoon job if you are handy with tools, otherwise pay a mechanic to do it
Beyond that, the car is really rock solid. Be nice to the transmission and you'll be fine.
'02 Aurora 3.5, factory NAV retrofit, CD changer retrofit, Philips Xenon lights. '96 SE: Gone but not forgotten :( Oh yeah, and a few other toys.