No. OmniFocus’ syncing feature has more complex needs than the apps iCloud was designed to support. Right now, the two aren’t a good match for each other.
One possibility would be re-designing OmniFocus to fit iCloud, but it would be a significant engineering effort–we’d need to build a new database format with iCloud-style sync in mind. We may do that in the future, but this would also mean putting all the other features that customers are asking for on hold until we were finished. For the time being, we’re hesitant to do that.
You are welcome to set up a free account on our own Omni Sync Server. (We may add additional for-pay services to the server in the future, but if all you need is sync access, we won’t charge for that.)