Yes it is but you cant just call it Tetris. You will have to call it something else such as Tetris Fun. EA owns the rights to the Tetris game this is why you cant call it that same name, but if you deviate the name a little then you can call it that.
Hey I'm intereseted in this copyright thing, too.
Working on a lotr bfme map. How about that?
Would it be okay to call it Alrik's Battle for Middle-earth,
or would it be a problem to use the correct names ingame,
because EA got the movie license for games?
I am not intending to publish it as a premium map.
Also is it a problem to copy the movies' style for
self-created models like Helms Deep?
It reminds me of an old Starship trooper map on sc1 that used the main theme also and never had any copyright problem on B.net 1. Well, as long as no one report it... :P