Are customs played a lot? I just bought SC2 for the Arcade games. I used to play a lot of Wc3 customs.

I have tried, Squad Td, Gem Td, and Element Td.

Both were a ton of fun with new graphics ect ect.

Was curious if there is a official thread or something for Arcade games where people discuss them or find groups to play with?

Yes many are playing Custom games - like the old Use map settings in starcraft 1