Let the hive mind of Engadget get that for you.
"As someone who doesn't reside in the USA, I was wondering what would be the best way to get internet for my computer in the US for a couple of weeks? If it were Europe I know I'd look for some prepaid data. Is there anything similar offered by American carriers? A MiFi or a data SIM that I can tether from would work, but I'm trying to maintain a tight budget. Help!"
One of the technologies is going to be obsolete on the day of the merger - and I bet its going to be Sirius. How long will they simulcast on both systems? Experience in Europe with failed satellite projects like Astra Digital Radio is that you can expect about 3 years before your set goes dark.