well the only way to tell if that turbo is kaput (besides turbine impeller blade damage) for now is to take the compressor side of the turbo's air inleft pipe off (right in the middle of the compressor when looking at it from the side) take that off, you will see the compressor impeller blade in there with a bolt down the middle.. grab the top of the bolt and move it sideways, and in and out, and if there is a lot of play (i'd say more than a mm) then yeah that'll be a prob, since the turbo wines roughly 18,000rpms+ and that shaft play will eventually get worse and worse.. later resulting in damaging the compressor housing yielding your turbo pretty much a door stop

if it's whining like a cat i would also check the return oil line back to the oilpan.. sometimes those like to clog and cause your turbo to have oilblow by the centerhousing's seals (either turbine or compressor side seals)

gl to you man
-brad