If the ECB does not act today (as the market is hoping) to buy more sovereign bonds, the EUR should fall because the sovereign bond crisis will still be going on.
If it does act today, and the market takes it as a normal QE, then the EUR should fall for the same reasons that the USD fell when more QE was on the cards.
If it acts today and the market takes it as dangerous monetisation of the debt — which would be right — that would be a signal that the ECB is not as tough on inflation as the market expects, and the EUR should fall.
Consequently, it seems difficult to lose money. Sadly that is never so in currencies. A relief rally could take out my position before the market focusses on the next problem.
If I was in their place, I would cut interest rates and announce a return to unlimited 12-month liquidity for the banks. The market is not expecting the former and the surprise might buy some time; the latter would make wholesale funding runs on European banks less likely.