I would make 1 small change to your main, -1 Misty Rainforest, +1 Volcanic Island.
I would not run the Pyroclasm. David McDarby said they were no good against RUG. Firespout is an option, but unless you are using a Petal to cast it (and pay G), it will not hit Delver and probably wouldn't kill a Goyf (assuming land, instant, sorcery in the graveyard). It could wipe the board vs. Maverick, assuming no Mother of Runes and Knight didn't get too big. Emrakul could also wipe the board vs. Maverick. So could Submerge.
Currently, I'm running
4 Leyline of Sanctity
4 Grafdigger's Cage
3 Echoing Truth
2 Vendilion Clique
2 Through the Breach
My meta is very combo heavy, hence the Cliques and Through the Breach (for the mirror).
I'm considering going rogue and cutting the Echoing Truths all together. Why, might you ask, is Water Wizard being so risky? Well, let me tell you.
a) We don't face much hate. Yes, yes, perhaps the meta is shifting. Perhaps we can expect to see more Ensnaring Bridges...
b) We can counter the hate we face. Just don't let them drop it in off a Show and Tell (that will ruin your party), but that's what Through the Breach is for.
c) We can race the hate we face.
Ensnaring Bridge = 3 Drop.
Humility = 4 Drop (w/ WW plus limited deck compatibility).
Peacekeeper = 3 Drop (Owwww, this card hurts - should I run Gut Shot? How about Sudden Shock)?
Liliana = 3 Drop (and activated at sorcery speed).
Jace = 4 Drop (and activated at sorcery speed).
Out of all of these cards, Ensnaring Bridge is the only one that really concerns me because: a) it's colorless and can be run in any deck, and b) it's the most likely card we'll face.
Is it worth it to go 'naked' against permanent based hate in order to improve other match ups?
Second, Leyline of Sanctity has been unimpressive. In general, I've been skeptical of running any Leyline in a deck that can't naturally cast it. Yes, you can shuffle it away with Brainstorm. However, I am not going to mulligan an otherwise good hand to find a Leyline. Perhaps I haven't played against enough BUG decks, the match up in which Leyline really shines, but against Storm, Belcher, and Burn, it's been underwhelming.
Jessenator, regarding your sideboard. What I gathered above is that you expect to face Maverick, UW Control, and the Mirror. Given that prediction, I would make sure your sideboard includes:
3/4 Blood Moon or Pithing Needle (Phillip tested 50+ games and Needle is better vs. Maverick and UW)
2 Through the Breach
2/3 REB/Flusterstorm - I don't think you need to run 2 of each (I don't think you'll have enough slots to take out).
4 Leyline
3 Grafdigger's Cage
The irony of this sideboard, and all S&S sideboards is that we dedicate considerable sideboard space to match ups we don't expect to face (i.e. Leyling for BUG, Junk, Deadguy Ale (heavy discard / creature sac effect decks) and Dredge/Reanimator (I know Dredge is a tough match up, but is it worth 3/4 sideboard slots? Probably yes, but it does get old to dedicate ~25% of our sideboard space to one match up (realizing, GDC is good vs. the Reanimator mu as well (but it is mainly there for Dredge)).
Does anyone else feel like going 'rogue', cutting down on the dedicated discard/edict/graveyard hate and utilizing those slots for match ups we expect to face?

