I’m listening to the Hanselminutes Podcast; \"StackOverflow uses ASP.NET MVC - Jeff Atwood and his technical team\". During the course of the Podcast they are speaking about SQL
Part of this is driven by the availability of non-relational datastores. SPs generally imply a relational database; ORM and Linq offer the the ability to create abstraction layers that are richer than SQL offers, and sometimes a better match for the abstractions we use in other parts of the design (the "impedance mismatch" problem.)
And it can also be considered a function of architecture. SPs imho match pretty well with a classical table-driven application, and can provide a convenient way to architect an abstraction layer at the business-objects level.
They're not so handy if your data store is xml, or an analytical database.