Given the fact that Final Fantasy IV is already ingrained in Western culture, this release seems rather pointless.
One thing to keep in mind about Final Fantasy II SNES is that it is based purely on the Super Famicom release of Final Fantasy IV Easy Type. Responding to numerous complaints that Final Fantasy IV was too difficult for casual gamers, Square Enix (then Square Soft) released a pseudo-update which not only made the game a lot easier, but also cut out a dearth of content including some character abilities (like Cecil's Dark, Rosa's Pray and nearly half of Yang's awesome Monk move set.) The story revolves around a Dark Knight named Cecil who must confront both the monsters that threaten the world around him and those that torment his soul. Only by becoming a Paladin can he cut through the Darkness, defeat Golbez and restore the world's four elemental Crystals.
Perhaps it is worth noting that the North American translation effort of Final Fantasy II SNES wasn't exactly top-notch and, given Square Enix's exemplary track record of quality localizations for most of their games, this is rather surprising. Yet, considering how many people think the game's poor Engrish is more along the lines of a laughable blessing than an irritating curse, most of today's gamers who actually played the original game don't seem to pay any sort of mind to such misgivings. You can't help but be amused by such spiels as "you spoony bard!" (perhaps the most oft-quoted line of Engrish ever) or "someone picked up a sick girl from Baron falling down." Or my personal favorite---"But you're a Dark Knight! It's not only your problem, but also ours." Not all of it is bad, and it isn't so incoherent that the overall story is adversely affected in any way. Uematsu's music sounds as timeless as it's ever been, and it still sounds wonderful on stereo speakers.
The gameplay remains largely unchanged, but those who are used to playing Final Fantasy IV on the PSX re-release, GBA port and even the recent DS remake may not find much reason to dive into this one. If you knew it all the while as Final Fantasy IV and suddenly see it as Final Fantasy II, it is very easy to get confused and perplexed unless you owned and played the original cartridge back in the SNES glory days. Thus, Final Fantasy II is a pretty tough sell to either audience. I suppose an acceptable reason for wanting to download it from the VC would be for the old-timer mourning the loss of the save battery encapsulated in their cartridge; longing for the opportunity to relive the good old days of Final Fantasy II, not IV. If you fall into the latter category (like I do...at least, most of the time), by all means. For everybody else, it is presumably better if you stuck with any version of Final Fantasy IV that you've got lying around.