And there are certain things that ESN doesn't let you subscribe to that you could figure out anyway if you poke around enough (and know where to poke). ("desh has posted a new private entry!" Or, more realistically, "Some random person you're not friends with just [un]friended desh!")

Some of the "missing" things on LJ are because they're just not that thorough yet, but some I bet are deliberate. Because LJ developers already know what Facebook devs will probably learn from user feedback over the next few days: there's a key difference between available data and easily available/aggregatable data. Moving something from the former category to the latter requires as much careful consideration as making the data available in the first place does.