They've already got progressive springs as standard.
I'd be inclined to change the fork oil if you don't know when it was last checked, and make sure the levels are spot on.
The level for 00/01 bikes are different to 98/99 bikes because you have the adjusters, so more internal metal work and less oil, so make sure you get the correct air gap from the manual.
And i don't know what build you are, but if you are of the heavier variety then try using 15w grade oil rather than 10w, i found it to make the front end much more stable, but then i'm no lightweight.
If you look like you need a good meal then stay with the 10w otherwise you'll find it a bit bumpy up front, although at least you can use your adjusters.
I've got older forks without adjusters on my 00/01 bike, but have had no problems at all.