Yeah, we've been bitten by this too, around once a year, even with our fairly reliable and redundant network. It's a PITA, your process just hang and there's no way to even kill it except restarting the server.
> intr / nointr This option is provided for backward compatibility. It is ignored after kernel 2.6.25.
(IIRC when that change went in there was also some related changes to more reliably make processes blocked on a hung mount SIGKILL'able)
Of course this is irritating if you're blocked waiting for something incidental, like your shell doing a search of PATH. In those cases you could just control-C and continue doing what you wanted to do (as long as it didn't actually need that NFS server).
However I can see that it would be difficult to implement interruptibility in various layers of the kernel.