As always when you see recommendations to "migrate" from Notes/Domino it turns out that it's only mail/calendar that is thought of.
In this instance we are offered a notion of a degeneration of the typical Notes/Domino environment into a myriad of business solutions that are disparate and impossible to maintain in an ordely fashion.
I miss just a tiny hint of how organizations will survive leaving the business solutions - and have nothing to put in their place!!
I have seen many "papers" on how to migrate from Notes/Domino to ... what ever i. e. Sharepoint, Google, you name it. NONE have been able to establish a shred of evidence of other "solutions" ability to deliver what Notes/Domino does.
If you go to MS - and read the recommendations of how you make the move - you see that only PART of the transition of (mind you) mail and calendar is a smooth ride (if you have no financial problems - paying a new huge hw-installation and an endless array of new servers), and that moving almost any, ever so simple Notes database is not possible!
One the most interesting pieces I've read on this subject is a blog written by a guy who - after a long carreer in the Notes/Domino world - happily made the leap into a job migrating a large installation from Notes/Domino to a MS Sharepoint environment.
After having fought this battle for a year and a half (as I recall) he had come a long way - BUT he recommended that other organizations - running a Domino installation should stay there!
If we look to Google's offerings I wonder what's in it - beside mail, word processing and spread sheet. I'd certainly like to know, but I haven't seen anything for a very long time - even from a company delivering Google solutions!!
That is the main thing here in Google, that's why it is the largest organization of all.