Lubrication of these bearings is something that needs to be done often. 'Often' meaning at least a couple times a year if you do much riding.
Suspension maintenance isn't done as often as it should be by most. Then you end up with 'squeaks' and such.
By the time the linkage is squeaking (again, assuming linkage and not the shock itself) there will most likely be some parts that will indeed require replacement (changing). Some will be ok with a good cleaning and repacking.
Use the best grease you can get. Bel-ray makes a waterproof grease that has been reported to be decent stuff. I saw a pint of it at a local bike shop last week..about $5.
Even with a decent maintenance schedule, the bottom shock mount bearing (in the unitrack knuckle) is likely to fail. It's a bit of a weak spot in the suspension (POS if you prefer). ;)
This happens to me all the time MadArrow. If the squeek goes away when you spray a little WD-40 on the spring, then it is just a squeeky spring. I notice it most when riding in the dust and it goes away when I hit water or hose it off. For me, it is not a bearing or lubrication issue since I disassemble and relube all these points for every 15 gallons of gas I burn. If that turns out to be your source of squeek, consider yourself lucky and lube up all the suspension components and keep doing it on a schedule. You won't regret it.
I was in GA this year at the GNCC with a brand new KDX, that i had just greased the bearings on and i was over at Jeff Fredettrs trailer, and my bike was squeking. He told me that the seals rubbing againts the metal on the pull rods and shock and swingarm are what is makignthe noise. so wehn i got home i took her apart and spread a little grease on the outside of the seals, and it went away.
i had just done all the linkage & swingarm bearings on my 95,felt great but after a short ride,with the bike off in the garage, bounced up and down on the seat to check that new plushness and it squeeked! aaaaarrgh! found out it was just the fmf pipe slightly touching the shock spring............DOH!