Pointed Discussion

sacrifice this to kuldotha rebirth on turn 2 and you can pay to draw a card.

Mostly worthless. When will wizards stop printing "can't block" effects? The old red spellbomb was 10x better.

Not too hot, but thanks to metalcraft, infect and sac synergy it still can be pretty useful. And it's cheap.

"Can't block" is still useful. It's an evasion variant.

I'm surprised to see this old slowtrip Panic turned into SoM's red Spellbomb.

It's interesting that three out of five of the new spellbombs so closely mirror the Zendikar/Worldwake common EtB lands.

So, what other effects could we have seen?
Kabira Crossroads- You gain 2 life. (Lame!)
Sejiri Steppe- Target creature you control gains protection from the color of your choice until end of turn. (Nice, albeit less so in an artifact set.)
Halimar Depths- Look at the top three cards of your library, then put them back in any order. (Flight is far more relevant.)
Piranha Marsh- Target player loses 1 life. (Lame!)
Teetering Peaks- Target creature gets +2/+0 until end of turn. (Panic is about equally interesting, and gives Trigon of Rage more room to breathe.)
Turntimber Grove- Target creature gets +1/+1 until end of turn. (Would have preferred this over Yet Another Braidwood Sextant; I love manafixing but hate shuffling.)
Khalni Garden- Put a 0/1 green Plant creature token onto the battlefield. (Origin Spellbomb's not far from the mark.)

OK, looks like they chose the best of the bunch. I do wish they had kept a tighter cycle, with no mana in any of the activation costs. White could pretty easily have gotten damage prevention (or Carom) or freed up Seize the Initiative's or Salvage Scout's slot. Fog, Bind, Provoke, and Lotus Petal are all interesting green options.

This is a lot better card than what it seems on the first glance.

For 2 mana RDW gets either an unblockable creature (it'd be surprising if the opponent had 2 blockers on turn 2) for no card loss (ok, they can do this with smoldering spires too but it's not like the spires cycle), *or* something neat to sacrifice to Kuldotha Rebirth.

Actually saw this in an interesting RG mid aggro build, used to get through damage, feed Kuldotha Forgemaster (the Forgemaster had some potential in the build, but unfortunately it was wasted on Plat Angel - Eldrazi Monument would've been pretty nasty though), and feed Molder Beast. Would've won him the third game too if he hadn't terribly misplayed with it (if you have one and they have no blockers, and you need to use it to pump to lethal, save it for the last possible second in case they flash something in!).

It's very kick ass in limited though. Card draw in red for 2 with a very relevant ability.

Forget drawing a card, this is for your green and black infect creatures. The early hits are the most important. The late game is for proliferation anyhow.

There's some scary infect decks starting to get built around this guy dropping on first turn, with no possibility of paying for the cantrip.

Erik's Random card 6/16/2011
This cycle used to work a bit differently. This was the Ruby Trinket (as in Trinket Mage).
Design tried out a lot of versions:

2 mana: When CARDNAME enters the battlefield, draw a card. R, Sacrifice CARDNAME: Target creature cannot block this turn.

2 mana: R, Sacrifice CARDNAME: Target creature cannot block this turn. Draw a card.

1 mana: 1R, Sacrifice CARDNAME: Target creature cannot block this turn. Draw a card.

1 mana: 2, Sacrifice CARDNAME: Target creature cannot block this turn. If you paid R to activate this, draw a card.

Development repriced the ability:

1 Mana: 1, Sacrifice CARDNAME: Target creature can't block this turn. If {R} was spent to activate this ability, draw a card.

After much testing, and thinking about the set, Mike decided these should work with the sacrifice cards. There are cards that want to eat artifacts, and wouldn't it be cool if they would work better with the Trinkets (now Spellbombs)?

1 Mana: Sacrifice CARDNAME: Target creature can't block this turn. When CARDNAME goes to a graveyard from the battlefield you may pay R. If you do, draw a card.

This works well with cards that want you to sacrifice an artifact. It also makes it more reasonable to play in a non-red deck; you save a mana. And in a red deck, if you are very mana tight, you can use it and forgo the card draw. Of course editors cleaned up the wording.
Why was so much effort put into this cycle? In part, these cycles say a lot about how the set works. Also, as a common cycle, you get about 0.5 spellbombs per booster. In a triple Scars draft, that works out to 12 of them. They help give metalcraft, and cardflow, so most of those 12 will be in people's decks. Getting them to be interesting goes a long way towards making the draft format more fun.

Gimme back Pyrite Spellbomb. RDW needs to crack some pro-red skulls.

It's utility for Kuldotha Red. I mean you can turn it into an clear path and a card, as part of the metalcraft count for Galvanic Blast, or fodder for Kuldotha Rebirth and a card.

While definitely not as versatile as it's ancestor, Pyrite Spellbomb, it's ability can be potentially better than that of Pyrite should you desperately need to get something through (Remember, Infect was in this block).

Furthermore, where you had to either choose one or the other with pyrite and both abilities required it to be sacrificed, this card can use both it's abilities for one red mana, and it's draw card ability can be triggered at any time it would be destroyed, so sacrificing it to shrapnel blast allows you to draw a card in addition to dealing the 5 damage to your opponent simply by paying one {R}, something not many artifacts can boast.