Over at Read/Write Web, they are currently running a poll on what form of feed reader their audience uses. Web-based readers (Google Reader, Rojo, Bloglines) have the lion’s share of the poll results.
However, like a few of the commenters, I agree that this poll is heavily skewed to the geek demographic. Services like Zookoda serve a large group of non-geek (and geek) users with push email of their news. News that is easily available via RSS.
I look to my wife, Alli, as the perfect example. She is a highly capable non-geek (she is in HR) who gets the vast majority of her daily news through push email, despite those sources invariably offering feeds. She knows about and “gets” RSS, but she doesn’t have the time or desire to invest in building the collection of her information sources as a set of feeds in Google Reader or somesuch.
Deliberate information consumption via RSS is still very much a niche space.