The upcoming patch fixes bugs / story bugs, but does not add anything. A list of fixed bugs will be released with the patch.
Most people are able to complete the game without running into any major bugs, and there is only one un-fixable story bug that I can think of (entering the castle by teleporter stones before getting an invitation, speaking to Janus and accepting a quest). I'd say go for it, but you wouldn't be alone if you decide to wait for the patch.