The blog world is full of posts about muxtape, which is the latest in a long line of playlist sites, imeem, projectplaylist, seeqpod, mixwit and now muxtape.
muxtape takes simple to ridiculous extremes, only 1 'muxtape' per account, 12 track limit, and max file size of 10mb. However many of the people who are calling themselves fans of the site clearly think this has made the site better than all the others which have been around longer.
Or, reading the blog posts about the site it's more likely that they haven't actually heard of the other sites and muxtape is their first experience with the world of online mixes.
The site appears to suffer from poor browser support, failing completely on my firefox install. However there's no real security and all the files are stored in mp3 format on amazon's s3 elastic storage service so it's trivial to download the files from muxes... errr mixes that you like. Which is nice because the other services have made compromises on their content to protect themselves from legal action, actions which have soured opinions towards these more established sites. So if you want to download Beatles tracks then muxtape with a bit of help from its friends at Amazon have them all available for you.
I give the site a couple of months before it makes changes to protect itself and triggers a blogger backlash.