I dont know what is the deal between them but I love this ability of Amarok. you give your last.fm user name and password to amarok and choose one channel and it starts playing songs one by one and I can say I like this or ban this. lovely kde and beautiful amarok.
there is only one problem about this. sometime quality of the stream changes and sound volume changes too. not a big bug but annoying.
anyway its been a long time I have not used linux for desktop this is good.