The decision about whether or not to delist Nikko should come in mid-March. So don't be surprised if more of these reports cause price swings in the company's stock.
On a related note, some reporting indicates that a delisting will play a major factor in what Citigroup eventually does -- such as Citigroup boosting its stake if Nikko doesn't get delisted. And trying to buy it outright if it does. Keep in mind, there is all sorts of speculation out there -- not to mention ongoing talks behind the scenes between Nikko, Citigroup and Mizuho Financial.
If you've followed my moves with Nikko Cordial since 2005, you're up nicely overall. I'm not selling my remaining ADRs. My advice for anyone in my position is to hold. But, as always, you have to make up your own mind.