I don't gamble on stocks but I like keeping posted on how tech companies are performing. i listen to a lot of tech podcasts and now I've added some tech stocks (mostly technology & phone companies) to Stocks app, and view them on the stock widget.
The notifications banner was borrowed from Android but Apple has definitely improved it. iOS before version 5 does NOT have glanceable information the new notifications banner (although it takes one swipe to view it) and the lockscreen notifications help out a bit. I'm sure users will love it when iOS5 goes live in the Fall of 2011 (no solid date yet)