I guess the new Retina Macbook Pros get pretty hot:
"There’s good news and bad news: while the fan was surprisingly quiet — even in an apartment with closed windows and some light traffic and rain outside, I could barely hear it — the heat was in the ballpark of what we’d expect from our personal 2011 MacBook Pro. Which is to say, hot — particularly the metal rim around the ‘U’ key, which is about where the processor rests internally. It’s hard to touch for more than a few seconds."