Rumor has it that it has 6 hull points, but the superheavy rules dictate that an explodes result removes extra hull points (d3... or 3... dunno, been a while). Sure, it has the invul, and the S:D chainsword, but as the rumors have it, I think it compares unfavorably to both Wraithknights and riptides.
All of that said, I'm going to hold out judgement until we get a codex.