When contacted about the item in question, YesAsia has twice responded that the item is indeed shipping, per information received from "their supplier." One response you can see here at our forums, another one was given to sailordees at Moon Chase. At the very least, then, the listing is not a mistake in YesAsia's product directory, and they do believe such a game is going to be released this year.

Something to keep in mind is that we don't know who their supplier is, and their customer service could basically have been looking at their website, seen there is a product there, and said yes that product is coming out. But, as I said, right now it's not a mistake according to YesAsia.

There was also news from earlier this week that Namco/Bandai and Toei are cross-investing in each others' companies.

I should note that I've searched Japanese-language news and nothing about the potential game appears. To give you an indication of how the blog rumor-mill works in English, though, just take a look at a Google News search for Sailor Moon. Those articles track-back to our friend aDam at powet.tv, which tracks back to the post at our forums, which tracks back to YesAsia.