We do.
The new Tyranids Codex is implying though the war isn't over, the Orks are starting to lose to Hive Fleet Leviathan. To be honest I wish GW would cut the whole "Nids can only be stopped by Spess Marines" thing out. I really do.
I really wish they had the Orks outdo Leviathan, if for no other reason then to give Orks more street cred to the average gamer. >.>