Packers have some wiggle room with 2012 salary cap - JSOnline. Luckily Tom Silverstein has "a source with access to NFL salary information" so I don't have to find one. The good news is that the Green Bay Packers have about $7 million in salary cap room. Some of that is going to the draft class of 2012. The rest can be used to re-sign free agents, most importantly C Scott Wells and TE Jermichael Finley.
That doesn't look like it's enough room to get the job done. Here's a complete list of the salary cap charges for 2012. A couple veterans (LT Chad Clifton and WR Donald Driver) could have their contracts re-done, or find themselves released, to create some cap room. The Packers could turn existing 2012 base salaries for players into a signing bonus, and spread it out over the remainder of the contract. So there are other things they can do to create additional salary cap room.
But the article does make it quite clear how difficult it will be to give Matt Flynn the franchise tag. A one-year franchise tag at $14 million with only $7 million of cap room doesn't add up. I've always thought it was impossible that they could tag and trade him, but I can't believe that GM Ted Thompson would allow a valuable asset leave without receiving anything back in return.