It really depends on the business. There are places where nosql is going to, rightly, kick out OLTP systems. There are places where nosql does not belong. Just as an example, I really, really don't want my banking to be done with eventual consistency.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning