Ok, just went and looked at the trade and here's my 2-minute reaction as a Raptors fan.
Meh.
I'm ok with losing Calderon because he's getting old. A starting lineup of Lowry, DeRozan, Gay, Bargnani, and Valanciunas actually looks pretty good on paper, as Gay is a big upgrade over Fields, but I don't think we can keep that together until Val gets enough experience to turn into the Top 5 Center he should become. I wish we could have kept Davis and got rid of DeRozan (since DeRozan makes horrible decisions and Davis was starting to perform well finally), but I guess they're ok with Val/Barg/Johnson as bigs?