I only really noticed GRRM doing it in A Dance With Dragons, his most recent book. Which is why it stood out so much. I was noticing names of people, places, even phrases lifted from Tolkien. I kind of get the impression he thinks he's showing how much he loves fantasy by including "easter eggs" like that... but it just looks crude and talentless to me.

I don't know. writers are supposed to re-invent the wheel I guess, but there's a difference between laying references to display your love or please your fans, and just being tacky.
in science fiction it works, and other situations i can't explain well, but in fantasy I think it would be a little harder to do

Eh, it is a different story with a some similar ideas. It works for a decent series if you don't read deep into it.