I just migrated pool to another datacentre (longer story later...). There are three loadbalancers behind every of following DNS:

stratum.bitcoin.cz
stratum2.bitcoin.cz
stratum3.bitcoin.cz

So nine machines filtering the traffic right now. Balancers behind stratum.bitcoin.cz seems to be dead from the attack, but time to time I see some accepted connection. Once the connection is established, it will be kept by the balancer (that's nice advantage of Stratum protocol).

Please try these URLs in your miners, some of them will, at least after few tries, work for you.