Technically, as long as you roll initiative within a round, it still works. Casting it when you believe you are walking into an imminent trap could be valid.
True. As written, it's only
almost completely useless. Still, that errata is actually a good thing.
Very situational, but what do you want for a 1st level spell?
Balance? Cyclone_Joker is right when he notes that winning initiative is hugely powerful, especially in the hands of a caster. Beyond the first few levels, the Wizard has spell slots to burn, so there's no real cost to this spell... and then he gets to end (or at least very significantly impact) the encounter before it really gets started.
If the spell included a proviso that the recipient couldn't use spells or spell-completion items (but not spell trigger items or spell-like powers), it might be okay.
Having said that, the proliferation of spells, powers, and magic items that make use of Swift or Immediate actions is itself problematic. Pretty much any such spell must be considered at least questionable in terms of balance, and most of them should be banned outright. (Because they fundamentally alter the action economy, by allowing two spells per round.)
Without reading through the rules, the fact that the spell allows this break does not automatically mean magic items do. I've never seen a Wand of Feather Fall, but a Ring that maintains its effect. Would we let someone walk around with a Scroll of Nerveskitter?
A
wand of feather fall wasn't possible until the Rules Compendium changed the rule on item activation. And since that was pretty much the last 3.5e book, it's not surprising they weren't present.
Having thought about it at some length, though, I don't think the problem actually lies with that rule change. After all, to benefit from it, the character would have to have his wand/scroll/whatever in hand and readied before the situation called for it.
The
real problem, and it's fundamental to 3e, is that many spells that are absolutely fine if the Wizard casts them once in one encounter per day, become broken if they're always active, either because they have very long durations or because the Wizard has slots to burn (or items to bypass Vancian casting). Monte Cook actually hit on this fact when he redesigned the Sorcerer in "Book of Eldritch Might".
If you reduce the Wizard down to preparing, say, any 6 spells of any level he can cast, remove all level-based variables (and reduce the duration of all buffs to no more than 10 minutes), and eliminate scrolls/wands/staffs from the game... well, casters are
still unbalanced (because there's no way to balance Power Attack doing 50 damage a round against a spell that casually rewrites the universe); however, it is at least
much closer.
Without reading through the rules, the fact that the spell allows this break does not automatically mean magic items do.
Incidentally, that was the point I made in the second of my 'deleted' posts. But that was also the point where I concluded I was being ridiculous. The inconvenient truth that Cyclone_Joker was also right (per RAW) also didn't help, of course.
But all that, of course, is
way off-topic for the thread. Sorry!