2004 TJ still going strong at 206k miles: What can I expect to replace next?

If you are using your trusted mechanic, ask him for a labor quote on the above and check the "How to" section here and see if there are items you want to tackle yourself. You may find working on Jeeps as a hobby is pleasurable, relaxing, and rewarding. It is my hobby here in the UAE and my garage fills up with 8-10 TJs every Friday with jobs from mild to wild. If you are not so inclined, a competent mechanic you trust is probably worth more than his asking rate. Honest shops with good mechanics should be supported financially and with good PR press. It isn't cheap or easy for those guys to keep their doors open.
 
You may find working on Jeeps as a hobby is pleasurable, relaxing, and rewarding.
I had a good laugh at this! While I tend to agree, I would say the split is about 50/50 between "pleasurable, relaxing, and rewarding" and "making up new and interesting combinations of tried and true curse words", "reducing troublesome older parts to miniscule bits of matter via the 12lb sledge", or "plotting (yet never undertaking, haha) the gruesome demise of some faceless, nameless engineer or bean-counter who's poor design or miserly decision has ruined my weekend".