All non-upgraded accounts are now either 512MB or unmetered. If you're using more than 256MB, you can request an upgrade to unmetered storage. (It's not quite unlimited, since there's a 50,000 inode hard limit and a max file size of 10MB.) It simplifies administration a lot compared to all of the various legacy plans that were almost but not quite the same (there were three or four different ways you could have a 1GB limit, another couple to have 512MB, new accounts would have different limits depending on which server you were assigned, the day of the week and the current phases of the moon, Venus and Mercury). Turns out that most people either use very little space or quite a lot of space; the ones in the middle (using between 512MB and 1GB) didn't amount to many accounts.