irius XM has provided its first performance guidance. On the customer side, the company said it expects to end 2008 with about 19.5 million subscribers and it will finish 2009 with about 21.5 million subscribers.Sirius XM said it expects to post pro forma revenue of about $2.4 billion in 2008 and revenue of approximately $2.7 billion in 2009. Also, it said it could incur a pro forma adjusted EBITDA loss of about $350 million this year. The company reiterated its previously stated financial guidance of about $300 million in positive adjusted EBITDA for 2009.