Steem has a marketcap of over $67 Million and 24 hour trading volume over 11 million.
It's not changing anything to any of them on a protocol level. Someone could just hang out on HIVE and not even know this other thing existed and nothing would change.
This will ride on top and provide extra rewards, extra functionality, and be marketed. Community members here could use it and tap into that or not.
RE: HIVE, STEEM, Blurt Reunification App And Integration To Top 50 Blockchains