I think that Live Mesh will be really useful. I think it provides great benefit to individual users, such as myself, and has great potential to be used by software solution developers. I'm presently using it to synchronise some files that I want to backup and be available wherever I am.
I originally had a lot of web files being synchronised, around 700MB, but the synchronisation was taking ages and killing my CPU. CPU was sitting at 100% and there was no sign of things completing. I think it was having a problem with the volume of small files.
To summarise: it's a great product with bags of potential but something needs to be done to reduce the CPU usage when dealing with the synchronisation of a large volume of small files.