I reboot my phone a lot—significantly more than most people, I assume. I have my reasons, none of which involve a tinfoil hat: usually I'm flashing a kernel, doing a ROM or radio update, trying to fix my mail client when it stops working with my Exchange Server, or just tinkering around with something new. This means I'm presented with a freshly booted OS quite often, which results in my recently used programs no longer being listed by long pressing the home key.
Often this also means I'm stuck scrolling through my overly large applications list trying to remember what the name of that application I've been playing with all day was called even though I probably ran it 20 times. Have you ever had so many applications that you realized you're only playing games alphabetically below D? I did.
It's a little short on features at the moment but it's pretty new, so there's a lot of room, and time, for improvement.
It takes running a few applications before it knows what you use, so there is a learning curve for it, but it will keep up with what you use most.
You can keep up with the development thread over on XDA and download the current product in the Market.