The lens is not really commonly available new, its just ancient stock that been sitting in a shop / warehouse for the last 10 years, would you really want to get one? Personally I wouldn't touch it with a barge pole unless it was a real bargain basement price. If so you could always buy one and use if for parts if it is so important to keep a copy running.
I thought it was just removed from the premium CPS service run by Canon, it will still surely be repairable by independant places. You could try H Lehmann in the UK, I used them once before, good service and authorised by Canon but you may find they carry a good stock of parts for older lenses.
As far as discontinuation of a premier service for a 10 years out of production lens goes I don't have a problem with that, afterall the whole point of CPS is to keep working pro's going with a quick service, they have to cater to those invested to more recent products so have to draw the line somewhere. Every time I have used them the quality of work and service time is impressive and not even that expensive with many lenses carrying a fixed price repair regardless of problems found. However if Canon as a company can't repair an older lens or at least look at it and advise what needs attention and work within the parts stock that must still be partially available it is a bit crappy, especially for L series lens.
It will be interesting to see how other still qualifying products last for CPS eligibility, I notice the old 5Dmk 2 is still there but the EOS 50D introduced at exactly the same time has been taken off on the list sent out yesterday, they must have sold a lot more 50D's than 5D2's and you would think availability of parts is related to final production numbers for a given model so how long will this old workhorse be supported?