The politicians, as always, place power, ego and hubris in front of everything else. Sarkozy is a small man, you have to remember, so the last thing he wants is a "weak" currency to go with his diminished stature. He wants a BIG, TALL, STRONG currency. BUT, the German export machine is in overdrive and will continue to thrive with a weak currency.
When the euro was 0.85 it was very oversold and the intervention then was effective. I don't think 1.25 is "oversold".. if it drifts to parity over the next few months, is that really a big problem for the real world?
(EUR/GBP still looks bloody high to me, if that came off 10 pct it wouldn't be shocking)