I'm due to receive an exchange Blackberry Bold handset tomorrow morning as my current one has a fault accessing the internet and email.

As a result, this evening I have backed my current one up using Blackberry Desktop Manager on my PC.

As I will be restoring my backed-up data onto a different Bold handset, would there likely to be any problem, or is the back-up and restoring only suitable if you are restoring onto the same handset?

I would recommend the Device Switch option within DM. Does everything you need including move the 3rd party apps.

If you won't have both devices present at the same time, I would recommend using the Device Switch wizard trick to get your third party apps backed up.

Here are the directions to backup your third party apps.