Recently I was quite positively surprised when I noticed that the apps I bought in the Ovi store are not locked to a certain device but are part of my account in the Ovi store. In other words, when I changed my device I could install the apps again free of charge on my new device. That's good to know since I tend to change devices quite often so I'm quite happy that my apps will follow me to a new device. Makes a lot of sense from a user point of view!
How about the behavior of other app stores, do they allow to do the same?