I see that the latest nightly build (thanks for that, Warren) is
still not compatible with Tails/Debian Squeeze. Is there still an
intention to address this issue? Might it be fixed by 0.9.2?
If I understand the situation, bitcoind does work but not bitcoin-qt due to qt-4.6? If that is so, then the official Bitcoin 0.8.6 binaries didn't work on Squeeze either this is not a regression.
The priority is for bitcoind to work on as many distributions as reasonably possible as older stable distributions are most often headless. If you are a rare user who needs Bitcoin-Qt on an incompatible system you can at least build it from source.