Ironically, a week before I'm hoping to get a Droid phone, I got a notice that Blackberry OS 5.0 was available for my Storm, so I upgraded - and it finally gets it right.
Some background: the Storm multi-tasks but doesn't bother to close programs you're done with, so it seems to run out of memory a minute after turning it on. (It doesn't help that there's no built-in process manager, and apps running at shutdown reload on startup.) The result is constant hangs - its equivalent of an hourglass or spinning beach ball, all the time. Sometimes it'll hang for minutes when a call comes in, so it's impossible to pick up. (I was literally on a boat once trying to hail the coast guard and it crashed.) It's got other problems too, but the hanging/memory/process issue is by far the worst, and is a product killer for me (and not in the good way). So I can't wait to ditch it and get a Droid.
Until I updated to OS 5.0, that is. It has a new process management system: the Back button, instead of returning to the home screen and leaving the current app open, now closes it by default. (You can still navigate to the home screen and leave the current app open, so it doesn't restrict multi-tasking if you want it.) So if I open GMail, click Back, open Twitterberry and click Back, open the browser and click Back, I don't have 3 memory-hogging apps just standing by eating up memory anymore. The browser is also a lot faster now; the UI is smoother around the edges; and it generally feels faster.
However, in setting up some configs again (which were lost in the upgrade), I still got several short hangs. So it's still not a 100% smooth interface. I guess it just comes down to the hardware in the end.
I'll be at a Verizon store shortly after the Droid comes out. But instead of picking one up immediately on the premise that it has to be better than the Storm, I'll give it a few more minutes' review - run a bunch of apps and see if it hangs, basically - before buying it.