UPDATE:
The miners are running and the team is working on the pool mining integration, this should all be done in 'a few hours' (less then 12
Just noting these 12 hours are up, so they should be fully online by this point.
We haven't yet seen a payment for a block solved after Swede posted this message, by the way. The next payment should contain such a block, but it might be several hours before we see one that reflects their full rate.
We'd know if they'd tell us. (No, I won't stop making this point. It's completely ridiculous that we're having to guess about this.)
After the 12 hours deadline, the slush's pool has already found 2 blocks, 258796 and 258803. Let's see the result of the distribution of that 2 blocks. Currently, 93 and 100 confirms are needed respectively. Considering the distribution delay, we need to wait around 18 - 20 hours. Let's see what happens tomorrow.