Hearthpwn

If this thing draws a Bomb it doesn't swap costs. I'm pretty sure it is a bug.

It kinda makes sense because the Bomb's "Casts When Drawn" causes it to go off before the cost-swapping, causing that effect to miss its target. At least, that's how I think it works.

 Murloc Paladin says hi

Interesting design but I'm sceptical.

Building a deck centered on this card means to include it twice to make the deck more stable. But it also decreases its potential, because, you may draw the 2nd  Prismatic Lens!

To make it work you need:

• either small dudes and big spells: So we might consider an aggro deck + Dinosize (and no other spells), and cross fingers to draw (the only?) Prismatic Lens very early. Problems:
  • Dinosize seems to be the only big spell that could be relevant.
  • It seems tricky to remove Lost in the Jungle or Blessing of Might for this (very) optimistic scenario...
  • Maybe this option will become more interesting in the next expansions...
• either big dudes and cheap spells: if you draw it very early it might work even if you run this card twice (just include enough low-mana cost spells to increase the probability to get a favorable combo).
  • If you can cast the Prismatic Lens early, your cheap big minion could hold the board an deal significant damage, a bit like an early Edwin VanCleef.
  • On the other hand, if you do not draw Prismatic Lens, I'm not sure that Paladin could hold the board by only using cheap spells and tokens. I guess that you would need Baku the Mooneater, Noble Sacrifice, Lost in the Jungle, Holy Light. And at the end, you will be probably overwhelmed...

It wouldn't be the end of the world to get a second prismatic lens because you could just cast it again for 1 (theoretically) mana. 

Right. And so the second Prismatic Lens could become worth if you were unluck with the first one.

design for swapping low cost spell with high cost minion, it can draw itself.

The card definitely looks appealing. I don't think it will see much play for a few reasons, mostly dealing with the 4 mana cost:

1. 4 mana + draw is actually pretty prohibitive. Hammer of Wrath hardly sees play and it can actually effect the board state. That means this is probably only going to see play in control heavy decks where a thinned deck has more controlled outcomes and you are more likely to be able to play a potentially discounted spell or minion on the turn it's used. But when you think about cards you want in a control Paladin deck you think of things like consecration + equality + doomsayer...those seem like they would be bad targets for this spell. So it's starting to feel restrictive in theory crafting a good use for it. In a quicker deck like Even Paladin wasting turn 4 or 5 to do nothing but draw is bad and offers way too much breathing room for decks like Taunt Druid to stabilize against you.
2. 4 mana is prime real estate in all versions of Paladin. It competes with a lot of other great cards like Consecration and a control deck trying to use this probably has consecration on auto-include which actually is a bit counter-intuitive because I don't think there's many minions you'd be alright with swapping to 4 mana. Edit: Maybe some kind of aggro variant can do shenanigans like put a lot of low cost minions in the deck along with Dinosize (making it 1-3 mana) and you can turn 5 Dinosize onto a Stonetusk Boar or something, but again a fast deck like that does not want to spend turn 4 doing nothing to the board state.

We have yet to see the rest of the expansion and of course we have no idea how the new meta is going to settle in so like many others trying to theorize how good a card is I'm probably completely wrong. I'm just having a hard time seeing how it's going to be real useful outside of a few insane highlight reels.

Probably the most interesting card in all expansion

That might be really good for expansive minion + cheap spell combo. 

Pink Floyd dark side of the moon 

Pink Floyd

well, 4 mana draw 2 that tutors a minion and a spell?

If you draw e.g. Into Argent Defender and Blessing of Kings, and you wanna play both it really doesn't matter which one costs which, but I find it really funny to draw into Argent Defender and Spikeridged Steed and Steed a Tirion.

All in All a Draw 2, Really.

Wait which card is Argent Defender?

You mean Righteous Protector, Argent Squire, or Argent Protector?

lol. He probably meant Defender of Argus since he put Blessing of Kings as his other example saying that they cost the same

no he meant protector, since he said "and you wanna play both". 4 mana draw these 2 cards and 2 + 4 is the remaining 6. 

Expectations: 1-mana The Lich King and 8-mana Repentance

Reality: Hydrologist and Equality

lol Quest pally but its just this Dinosize spikeridged and lay on hands 

You better be ready, my secret paladin's one mana C'thun is here, and he comes with a vengeance, or a Bronzebeard explorer rather.

Got a ten mana repentance ready to counter the next Pyroblast too.