I read on a site somewhere that the return of Daniels to the Boston roster was cause for (minor) celebration.

Say what?

You know a team has issues when someone points to Marquis Daniels' return as a reason to be happy.   I think that Boston are experiencing the same dilemma as San Antonio, and having a full roster won't alter it one iota.
It's called 'age'.

I also think that they realise it, and that's why they're shopping Ray Allen - amongst others - to try and patch things over.I don't think it's gonna work. We always knew that the selling-the-soul for KG et al had a limited shelf-life.

I'm going to call Boston's window of opportunity closed.

Could they get lucky and make a run? Sure. KG's knees might hold up, Allen might turn back the clock and Paul Pierce might find another wheelchair to get motivated by. But I doubt it.
I don't think you'll EVER see KG as the KG of old. There'll be instances during games, and maybe even the odd game... but he's not even a top 5 PF in the league any more. Hell... is he even top 10? I'd go so far as to say 'nuh-uh' on that too.

Not that I think Boston regret the move (or even should).  They got a title out of it, and that's more than was in their future prior to the landing of Garnett/Allen.  But it has put them in a bit of a spot now, and just like LA-fans, Boston's faithful aren't particularly forgiving as far as not-being-top-of-the-tree.  Especially after having enjoyed a recent title.

Pressure's on Danny Ainge... watcha gonna do?