I have a V70 AWD (125k) which started out making a weird whirring noise at high speed, then progressively worse clunking until there was a definity rotational clunk which could be heard half a block away. Went through a lot of non-diagnostics looking for the noise before actually wiggling the drive shaft, and viola, there it was. (Dealer didn't find it, two indy's did, and neither of them thought it was a big deal, but that I should repair it sometime (fcp groton drive shaft $860). In the meantime, it has stopped rattling - one mechanic suggested that it's due to the rubber shrinking in the colder weather, and since it's been such a warm winter to date . . .
In conclusion, isn't the the worst that would happen is that I'd suddenly have a front wheel drive instead of AWD? I've heard that some people just take the darn thing out.

Any thoughts?