No, it's MUCH worse than Lava Spike.
The thing is, on turn 1 you don't want to be playing Lava Spike. You want a friggin Jackal Pup more. Every turn your opponent can't deal with it, 2 damage. That can add up, especially if you're going first.
Therefore your opponent gives you the Lava Spike. Ooh, +1 damage. You're still not putting any pressure on him.
Later he realizes "Hey, I've got a real creature that can block that. Sure, throw out that 4/3." Or he just goes for its throat, or introduces it to Wrath, or sends it to Oblivion with a Ring, etc.
Same issue with Browbeat, only instead of more cards that can be more burn spells it's a creature that can't be anything other than a 4/3.
Interesting cards so far
Temporal Mastery - OBV
Thunderous Wrath - 5 damage is sexy. Very sexy. If UR Delver runs Temporal Mastery this will show up as at least a 2 of. Winning the game is nice.
Sigarda, Host of Herons - Awkward casting cost? Sure. But if there's decks that aren't running sweepers, this card becomes hax. Obviously miserable at the moment thanks to Black Sun's Zenith, but that card will rotate.
Arcane Melee - The interaction between this and flashback costs is kinda sexy. It needs something more to get going, and 5 is a lot, but obvious combo pieces should never be ignored.
That's literally it. Every other card except the white miracle card looks terrible. Angel of Jubilation might see some sideboard play in a mono white deck if a REALLY weird deck comes up. That's it.
