Yeah we have our own blockchain now that is in testnet (so basically DTC rewards are worthless, just for fun).
If you login with STEEM account you can still do all the actions you did before (publish video, vote, comment, resteem). The follow/unfollow got moved to the new chain though because we think it's better to have a separate follow list for only dtube. The new chain also allows new options, such as tagging content as a curator (your votes influence the video's tags).
For full info on why the new chain I wrote a long-ass article about it: https://steemit.com/dtube/@heimindanger/the-core-concepts-of-dtube-s-new-blockchain