It sure looks like Sony Ericsson is keeping itself busy these days, with the company now following up word of its latest hardware with an announcement of its plans for its upcoming PlayNow Arena service. That, as you can probably guess, is an upgraded version of the company's existing PlayNow service, although it seems that it'll be a good deal more than just a music service. There will still be plenty of goodies on that front, however, including the TrackID service mentioned on those new handsets, which'll let you identify a snippet of music off the radio and then grab it straight off the PlayNow Arena service. Even more interestingly, Sony Ericsson says that Arena will be an "open multimedia platform" that "welcomes everyone," which it says will lead to an even wider range of games and other "mobile entertainment experiences." It also promises to be compatible with a "wide range" of Sony Ericsson phones, although the company isn't getting much more specific than that at the moment. Expect to hear plenty more in the coming months, however, with the service itself set to roll out in "selected markets" in the second quarter of next year.