2 things regarding the possibility of Pierce leaving vs nostalgia and whatnot:
1- Many many many great, amazing, beloved players have left their original teams late in their career and been overpaid then faded away a couple of seasons later. Nique, Hakeem, Jordan, Malone, Pippen, just to name a few. It happens...and while its strange for a little while, at the same time it doesn't tarnish the legacy.
2- If the Celtics overpay Pierce and/or Ray Allen and the years go beyond 2011-2012, even when Garnett's now albatross contract comes off the books, the Celtics will still have little to no cap flexibility, and conceivably will be in a pretty terrible situation of having a gargantuan payroll while at the same time being a completely mediocre team. Basically, it would be like this year was, if the playoffs had not gone the way they had, and we would've been bounced by the Heat or Cavs. Nobody wants that. Personally, I'd rather watch a team that has low expectations and flexible payroll with eyes on the future barely make the playoffs than watch a team with no future and a huge bloated payroll barely make the playoffs.
I'm not saying I want Pierce gone. I want him back. But if he wants to get paid (and don't say he's 'looking to secure his future'...if he hasn't secured his great-grandkids' futures with his 100 million plus in salary he's earned thusfar, than whatever extension he gets now ain't gonna do the job either.), that's fine. He's won a chip here, he's always going to be a legend in green. There is no shame in taking a huge payday from a desperate team. But that desperate team should not be the Boston Celtics.