I agree. Being acquired by Twitter just makes it more likely that SoundCloud will fail, to me - have Twitter actually come up with a decent monetisation strategy yet?
If twitter shuts it down or ruins it, there will be blood. A lot of people depend on it and there would be instant demand for a replacement if the userbase turns its nose up at any changes.
OTOH anyone promoting their music on SC is almost certainly already doing so on twitter as well, so some simple, well executed integration could go a long way.