The word cloud is a crock and i'm not going to get into that.
But the general point of people providing online service based applications is that from many front ends they have one back end. Having it locked down to a platform is utterly utterly pointless and pathetically purposefully divisive.
I really am quite sure the future of modern global interpersonal communications is utterly disastrous given the state of rival networks fighting it out instead of working towards inter-operable-fault-tolerant-distributed-vendor-agnostic solutions.
Email is still the best way of doing this but as Instant Messaging has shown for the past 20 years (no standard ever caught on) without that we end up unable to communicate reliably and one logical place with everyone. The only thing even close has been SMS.