Not sure if this is accurate, but was watching Cohh play this a bit earlier today and he said that a while back they said they were going to either hotfix or do a large patch. He isn't sure the large patch is still coming since they have been constantly putting out fairly large hotfixes. They don't have the team size to do several hotfixes a week while also doing a major patch alongside it. Instead of it being very broken for a month, then release a large patch, they've released 1-2 hotfixes every week.
I'm still waiting for it to at least turn to 1.1 before playing it though. From what I've understood Act 1-3 had quite a few bugs, but playable. Act 4 onwards were very bugged. Now Act 1-4 is somewhat fixed while Act 5 onwards still have quite a few issues.