Sprint Nextel (S) shares are rallying today ahead of the company Q2 earnings report due before the start of trading tomorrow morning. The Street consensus is for revenue of $9.17 billion and profits of 3 cents a share.

In a preview note this morning, Bank of America’s David Barden says that Sprint’s big focus in the quarter was reducing customer churn. “How churn’s improvement impacted net subscribers will be a key focus for the market,” he writes.

Morgan Stanley’s Simon Flannery
said in his own preview note earlier this week that the “wildcard” for the wireless industry this quarter is the magnitude of Sprint’s subscriber losses. He notes that both AT&T (T) and Verizon (VZ) posted “strong subscriber counts,” which he says either means Q2 was simply a healthy quarter or that Sprint and T-Mobile “may be experiencing more pressure than anticipated.”

Other things to listen for:

  • Any info on the impact of the Apple (AAPL) iPhone 3G launch.
  • Any update on Clearwire, (CLWR), which is now Sprint’s partner on WiMax.
  • An update on the company’s strategic review.
  • Cap ex guidance.

Sprint today is up 36 cents, or 4.2%, to $8.47.