I would hope that it would be a prelude to different currencies in eve, as farfetched as that idea may seem. It would open so many options and may cause some very interesting effects on the market (decentralisation in particular). I don't see why nations that are on the brink of war should keep a common currency anyway...
ISK is the "space" credit....i believe each empire already had their currency, and there was some indication that even each planet had a local currency.
In the storyline, it would be quite detrimental to CONCORD if suddenly the empires took over the space economy and controlled it with their own currency.
Indeed, I meant that the accepted currency for commerce in space in territories under different sovereignty could be different, and could change with sovereignty - this would also apply in 0.0 stations, which could show a prejudice against a certain empire's/faction's currency. Let's not even get into the idea of alliances creating their own currencies (value optionally protected by some sort of 'gold standard'). This would give more meaning to 'factions' and alliance warfare. It would also make the mechanisms of currency exchange interesting, especially if certain currencies could not be converted into each other (e.g. Amarr-minmatar).
Re: CONCORD - the bastards couldn't resist the Elders attack so let them suffer...in Yonis we trust.