Sony Ericsson's PlayNow Arena has just been given a boost, with a plan for unlimited downloads and an agenda to roll it out to wireless customers worldwide.

PlayNow Arena fully launched in the Scandanavian countries Denmark, Finland, Norway, and Sweden in August, offering mobile entertainment content for Sony Ericsson users. The service uses a "cover flow" type interface to sell music, games, ringtones, and other phone content.

Today, the company announced the service, which has been in the works all year, will soon include an unlimited subscription option called PlayNow Plus, which will compete with Nokia's Comes with Music service. Like Verizon's V-Cast and Rhapsody partnership, the content is not limited to the user's phone, and can be obtained on a PC as well.

Naturally, Ericsson's homeland Sweden will be receiving the service first, through Telenor in the fourth quarter of 2008; and as PlayNow Arena expands to the UK, the Netherlands, Belgium, Austria, and Switzerland, so too will worldwide rollouts of PlayNow Plus. Monthly subscription charges have not yet been detailed.

To encourage uptake of the service, Sony Ericsson will sell PlayNow Plus phones pre-loaded with 1000 of its most popular tracks. Users will be able to keep an unspecified number of DRM-free tracks from the service even after they cancel their subscription. Some reports have put the number as high as 300 tracks.