According to the article, it's the end of 2010. And Philip Morris wants to buy out the 2010 contract, so he can ride for Ducati in 2010.
Yes, Rossi is under contract through the '10 season, just like Lorenzo, Stoner, Hayden and Pedrosa. If Phillip Morris wanted to buy out Rossi's contract to put him on a Ducati, they would also have to buy out Stoner or Hayden's contract to open up a seat.
Rossi's pissed because Yamaha signed Lorenzo after a deadline? Are they insane?! Yamaha sets the deadlines if there are any. Usually, the teams want to have their riders signed by a certain time so they know where they stand for the test the day after Valencia and can be prepared. Now with limited test rules, there is no room for missing a date. The bikes don't just materialize out of thin air, it takes time to build them.
Also, Yamaha wanted Lorenzo bad enough that they would and could wait a couple of extra weeks for the decision to be made. Since he wouldn't be a new rider, they knew what they had when building a new bike for him.
It's well known that Rossi doesn't like Lorenzo. He's openly stated he'll ride for another 5 years just to keep Lorenzo from winning the championship.
I doubt he'd ever go back to Honda. The bosses are gone, but the culture is still the same. He left not because Yamaha had the better equipment, but because Honda had screwed with him and he wanted to make them pay. Honda later screwed Nicky to benefit the midget and we all see how that's paid off.