Gainseeker,
Let me see how basic I can make this and if it is more clear this way? I'm keeping it simple in order to help clarify it a bit. Anyone can chime in and correct me if I am wrong.
(to my limited knowledge because I haven't really been paying attention to the satellite merger that much)
SIRI will be the company the two companies merge into (if they merge). Under the merger, SIRI has to replace XMSR shares with SIRI shares. SIRI will be the symbol under which the new combined company would be traded under.
XMSR trades at a higher price so it would not be fair to them to get one share of SIRI stock for their one share of XMSR stock. Based on an earlier calculation and a valuation of the company, XMSR shareholders will get 4.6 shares of SIRI for every one share of XMSR when they merge. (This will probably change since XMSR and SIRI have both dropped in price)
The XMSR shareholders will see the adjustment to THEIR shares not the SIRI shareholders as they are merging into us.
so to answer your question...your 1000 shares of SIRI will remain 1000 shares of SIRI and your price per share will be whatever the stock is trading at on any particular day due to normal market activity. There will be no adjustment to YOUR shares or the Price per share directly by the company.
(Heavens! I hope that's correct because Like I said...Haven't paid much attention)