DK tanking spec in the pre-patch

I'm new to classic wow and the phasing states. I know at launch in wotlk frost was the tanking spec for dk's but was changed to blood in a later patch.With the prepatch not being the actual release will frost dk be the way to go for tanking until release or will it already have the updates applied and be blood? Not a lot of resources available and I don't know what priority applies during the prepatch for the "phases".