You're not in trouble, and as TOY2G states ask your dealer. Off the top of my head this is what I would do:
Spark plugs
Air filter
Throttle body cleaning and MAF cleaning
Lube chassis/driveshafts
Front diff oil
Rear Diff oil
Transfercase oil
ATF fluid change (drain and fill is fine)
Replace belts
That should get you another 100,000 miles. Other ideas?
That's what I did to my 3rd gen, maybe the 4th gens are differnt in some ways.
IIRC, our Owner's Manual should have a schedule for service. Just follow that, its pretty well thought out. But that list above is a good starting point.
I would also add:
-A can of Seafoam (if you don't use it with oil changes already)
-Cabin air filter (if it hasn't been changed recently)
-Flush your coolant (drain and fill is good, but you can do a full flush if you want)
-Inspect the vehicle (CV joints, brakes, shocks, bushings, ect)
-Change brake fluid (if it hasn't been done in 30k already or is very dark and burnt smelling)
-Check the P/S Fluid, maybe even flush it if you want (For the most part as long as its fairly golden colored or red [some people use ATF, which is acceptable. See owner's manual for specification] it should be good, but I would just flush it if its got 100k on it)
Oh and be nice to the old gal and get her all prettied up! Nothing like a good waxin' and detailin' to make her shine! :hatsoff: