That last spot could have gone to Joe Johnson, Turko, or Jose. JJ is having a terrific season as well so no arguments from me. If Ray Allen made it over those 3, then I would have been a little peeved.
man this one is bad, people were complaining about VC possibly getting in as a reserve with his (21,5,5, on 45%) still an incredible season for anyone not named Vince Carter . So instead Joe Jonhson? oh my! 21ppg scorer on an Atlanta team who early on were teasing, but in reality are still a terrible squad.
The worst part? he gets his 21 (on his terrible team in the leastern conference) while struggling to shoot at 40% from the field 
(currently exactly at 40%)
as for Calderon, he's having one of the greatest statistical seasons ever! shooting 50% g, 40% 3pt, and 90% FT, if you're wondering only 4 players in the history of the league have ever done that for an entire season! oh yeah and I should probably mention his amazing assist/turnover ratio, he's going set an NBA record! All this while leading a winning team that currently sits 5th in the conference and has 7 more wins than Johnson's hawks...