While I voted it 'very good', I'm a little hesitant - it's a 3/2 for 2 with 1/1 of those stats being fast, with a potential Play Dead rolled in. That Play Dead is the key though, as otherwise Fallen Sun Cleric is basically strictly superior.
Just looking at the currently known mechs with deathrattle. These ones might be alright:
Meat Wagon (for 5 mana you get a 2/1, 2/5 and a minion with 1 or less attack from your deck) Harvest Golem (for 5 mana you get a 2/1, 3/4 and a 2/1) Spider Bomb (for 5 mana you get a 2/1, 3/3 and destroy a random enemy minion) Plus those bombs from the new hunter legend. Actually gets their attack off 0 - allowing them to suicide somewhere - and gets a 2 damage ping off the bat.
In addition, in wild it works well with all 3 piloted mechs, though pushes their costs up to 6, 8 and 10.
Mechanical Whelp + Fireworks Tech = a 7/7, a 3/3 that turns into a 7/7 on death, and a 2/1. If you slap a Spider Bomb on the whelp first, it becomes a deadly shot that you can Play Dead or Terrorscale Stalker at will. Basically, they need to transform it while also clearing the 7/7 before it hits them in the face, and you only used two cards to put them in this situation.
I don't believe in this card as a combo enabler, but I do believe in this card as an aggro tool. Hunter needs two more deathrattle 1 drop mechs, though. I believe hunter will get another 1 drop mech with deathrattle, but I think unfortunately we won't be granted a third one.