Unless a clutch has been greatly abused the friction plates are usually good.
The main thing that could go out is the damper plate that has the rivets in it (more a problem on the 97/98 models) but again...isn't a regular problem.
http://www.partzilla.com/parts/search/Honda/Motorcycle/2000/GL1500CF+A/CLUTCH/parts.htmlThe damper plate is #6 in the diagram.
You may also want to replace that bearing #21 while in there if a lot of miles and it was noisy but again, I bet it will be ok.
The other thing you may need is the cover gasket, #2 in the diagram below. Sometimes you can get the cover off without tearing the old one up but sometimes you can't. Wouldn't hurt to have one on hand if you are pulling it. Those two oil seals #14 & #15 might be a good idea to replace because of age, they might start weeping after being disturbed.
http://www.partzilla.com/parts/search/Honda/Motorcycle/2000/GL1500CF+A/CLUTCH+COVER/parts.htmlUnder normal use the clutch is pretty solid and will last the lifetime of most Valkyries. DDT's Ally (99 Tourer) has over 480k miles, original clutch.
One of my Valkyries, a 98 Tourer, was having no trouble with the clutch but at 100k miles decided to pull the cover just to check it (because of rivet problems on some 97/98 models) and when I pulled the clutch pack apart, no rivets were missing but I could rotate the two parts of the damper plate a good quarter inch. That meant that every rivet was notched and it was just a matter of time before it started losing rivets. If your bike is a 99 or above, I wouldn't worry about it. If 97/98 and abused or high mileage, wouldn't hurt to check it at least for peace of mind. I tour long distances on my bikes and do preventative maintenance to avoid being stuck in the middle of nowhere.