Wyc Groubek did state that there was a scenario by which the Celtics would be able to sign a max level free agent this summer. I don't remember if that was before or after he signed Wallace but clearly I think he had a feeling Pierce would opt out early. So perhaps they did think Wallace would retire after a year.
He said it before the Rasheed signing and the Rondo extension, I believe.
I think people are over-thinking Danny's foresight with the Rasheed deal. If the team's plan was to trade Rasheed's contract in the second year all along, why give him a third year (which was fully guaranteed?) Why not just make the second two years non-guaranteed? The reason is because Rasheed and his agent bargained for those extra years, because at the time they thought Rasheed might want to extend his career.
They cleared out an extra roster spot getting rid of Marcus Landry and then signed two CBA guys to contracts that in 2010-11 would be over the league minimum(hence counted in over the salary cap trades) and non-guaranteed. Why?
Both Gaffney and LaFayette have contracts for the minimum for guys with a year's experience. As for them being counted in trades, even minimum contracts can be counted for salary cap purposes if they're needed to make salaries match. (On the other hand, they can also be traded to teams without cap room, etc. For instance, a team can trade ten minimum guys for one guy making around $6 million, or they can trade ten minimum guys to a team for nothing.)
I do think, though, that there's a benefit to having two non-guaranteed deals at the second year minimum, rather than on rookie minimum deals. It adds roughly $750k or so in flexibility.