The major IM players tend to guard their protocols and do a "rolling upgrade" to them so that as new protocols are instituted users don't have to immediately update their clients. In other words the servers generally can handle more than one version of the client protocol.
But people do sniff sessions and publish documents on these protocols or even develop their own client software... and even components that provide basic client capabilities. This is tough though, if you obtain such a component it may stop working in a year to 18 months.
The idea behind the changes is security improvements and reining in "spam bots."
Personally I get enough biz-spam at work from software that somebody thinks needs to shove an alert down my throat as an email. I'm not sure I'd welcome more coming in through a messaging client.
Unless the thing is truly urgent, I'd rather see these "alerts" and reports published as web pages. Then there could be an updated "links" page that offers me a quick way to scan through recent alerts and click on any I really wanted to see.
Email abuse for these things has reached biblical proportions. Leave my messenger alone! ;-)
