Everyone is blogging about it, and I was about to discuss its pros and cons in a comment to another post. That comment would've been like a blog post, so I turned it into one.
Okay, so, there's all this hype that X-Saber Anu Piranha lets you drop XX-Saber Faultroll after a Rescue Rabbit play, just like what Rescue Cat allowed for a year ago in the TCG. Or, you could Special Summon two copies of Gladiator Beast Andal to fuse them for Gladiator Beast Essedarii.
Rescue Rabbit is a good card, but I think that it invites dead draws. I mean, drawing Anu Piranha or Andal isn't horrible, but they're not exactly good, either.
For instance, if you draw two Anu Piranha, then all of your Rescue Rabbits are dead. So, in addition to your two vanilla beaters, you also have up to three 300 ATK vanilla beaters sitting somewhere in your deck.
Yes, the chances of drawing two of your three Normal Monsters is low (about 5% for your starting hand, actually), but there's another problem with this. Unless you run multiple sets of Normal Monsters, then you can only use one of your Rescue Rabbits, for obvious reasons.
Not to mention that the X-Saber play is lackluster (it's not like you'd have a Tuner to go with the Faultroll). However, the Gladiator Beast play is quite good. Due to the nature of Gladiator Beasts, you can easily put the Andals back in your deck, even if you decide to use them for an Xyz Summon instead of a Fusion for Essedarii. Speaking of which, Konami may have actually thought Rescue Rabbit through... If they had allowed Essedarii to tag out, then Rescue Rabbit would be worse than Rescue Cat in Gladiator Beasts...
While its best fit would be in Gladiator Beasts, Rescue Rabbit may also see play in HERO builds. I mean, some of the Normal E-HEROes were pretty decent, and worked as good Fusion Materials. The main one would be Sparkman, of course; Clayman is okay, too. So, you could Special Summon out two Sparkman, Xyz Summon Steelswarm Roach or something else, and have the Fusion Materials for E-HERO The Shining ready to go for later. While not an amazing play, it's not a horrible play, either.
So, Rescue Rabbit does open up a variety of new plays for practically everyone (maybe not Scraps...), but using it carries inherent deck-building restrictions (except for Gladiator Beasts, I suppose). If you want to actually use the effect of Rescue Rabbit more than once per duel, then you need to run multiple sets of Normal Monsters. But, that takes away a huge amount of power from your Main Deck. Xyz Monsters aren't really powerful enough so that you can rely on them, so making a deck based around Rescue Rabbit (that's not Gladiator Beasts) is kind of ridiculous. Besides, you might not even draw the Rabbits; you might just draw a hand of Normal Monsters...
Oh, and for the impending doom that will be Gladiator Rabbits, use Gladiator Taming!
"Ha ha, I Normal Summon Rescue Rabbit and banish it to Special Summon two Andals from my deck!"
"Reverse card open! Gladiator Taming! I'll take control of one of your Andals!"
They lose their whole play, and until they can recycle one of their Andals, the rest of their Rescue Rabbits are dead draws. Or, you could just use Dark Trap Hole...