"In our last fiscal year (July 2008-June 2009), more than 4.7 million people began the switch to Exchange and SharePoint from Notes", Exchange marketing director Julia White posts on the Unified Communications blog.
Cost savings is the number one driver for migrations, according to the post. Another key driver for migrations is the launch of Exchange Online and SharePoint Online. If you're considering the move to cloud-based services, Microsoft services offer plenty of choice for customers of all sizes. Julia notes that large Notes shops - including Coca-Cola Enterprises, GlaxoSmithKline, and Ingersoll Rand - are making the move from Notes to Exchange Online. Read more in Millions Switch To Exchange And SharePoint From Notes on the Unified Communications blog.