Will Virgin Mobile USA go public? The IPO rumor has swirled around the popular MVNO since it launched its service in 2002. The company, which is a joint venture of Virgin Group and Sprint Nextel, has 4.6 million subscribers, most of which are in the desirable teen and young adult demographic group.

But now that Virgin has some significant competition for that highly-desirable subscriber group--from traditional operators and other MVNOs such as Amp'd Mobile--some are speculating that the company will file for an initial public offering soon before it gets trampled by the competition, and because part-owner Sprint is unlikely to roll Virgin into its existing business.

For more on the Virgin speculation:
- see this article from BusinessWeek