I don't think we can make too much of what Danny says; obviously he's not going to show his hand to the entire media. He may just be talking a tough game as part of the negotiations.
I know he wants to pretend that he's Scott Pioli or Theo Epstein, but Danny also has to understand the situation the Celtics are in. I'll admit that I was pretty upset when guys like Ty Law and Johnny Damon left, but the Pats and Sox had two luxuries that Danny doesn't have: time and money. In both teams' cases, they still had a fairly young core: the likes of Tom Brady and David Ortiz had many years left when those decisions were made. Furthermore, when Lawyer Milloy left, the Pats got Rodney Harrison to replace him. Similarly, when Damon left, they nabbed an OK replacement in Crisp, and traded for Beckett and Lowell.
That isn't happening here. With Pietrus and Maggette gone, this list of replacements is drying up. Furthermore, with the age of the Big Three, Ainge can't afford to say, "we'll get 'em next year" and call next year a quasi-rebuilding year. And I know people like to say that Posey is just a role player, but we had some awfully close calls last year in the playoffs. A couple plays that went the other way could've meant a second (or even a first) round exit for the C's. And that's not something exclusive to this team. There were quite a few times in Russell's many titles that they eked out 2 point wins in 7 game series.
Overall, I think Danny needs to get this done somehow. I don't really want Posey more than 3 years; however, if it keeps him around and we get another couple titles, I'll take a couple dead years at the end. If anything, we've learned large expiring contracts have value in this league.