That product line, of course, is Xperia, Sony Ericsson's smartphone line.
According to European trademark filings spotted by PocketNow, Sony is releasing something under the name "Xperia Play" -- a name that would make sense for a Sony Ericsson phone designed to play games, which is exactly what the rumored (and very well-photographed) "PlayStation Phone" is. The Unofficial Xperia X10 Blog found XperiaPlay domain registrations set up by a marketing firm that works for Sony Ericsson. Pocket-Lint reports a rumor that the phone will be revealed at February's Mobile World Congress for an April release.
None of this is any guarantee that the "Playstation Phone" will be released as the Xperia Play -- or even that the Xperia Play name will be used for anything -- but in our opinion, it would be a pretty huge mistake to torpedo the product by associating it with any brand other than PlayStation. Perhaps Sony will launch an "Xperia Play Mobile App Store Powered by PlayStation" or some similar confusing half-step.