It feels like a new eReader is announced every month or so these days. The market that languished for years is now booming with new devices and a growing number of content sources. Perhaps eReaders are finally having their iPod moment.

Today Barnes & Noble is set to announce a new eReader — perhaps the rumored Nook device the NYTimes and Wall Street Journal leaked — which will be the third one attached to their eStore. Just a few weeks ago we got a glimpse at the IREX reader, a 3G-enabled device that will allow instant access to the B&N eStore. Earlier this year Plastic Logic announced their partnership with the bookseller and recently the large-screen device got a name: the Que.

B&N is certainly looking to one-up Amazon in the eReader department. Not only will they have three devices, but each has at least one feature that makes them compelling and will hopefully increase usability. Because they were developed by (different) independent companies, the readers aren’t locked to just the B&N eStore. With the EPUB format gaining more ground and more content distributors (Google Books and over 200 participating bookstores), consumers have more choices and publishers have more options. B&N still has the edge, as over-the-air purchases will likely be limited to their store.

We’ll have more information on the Nook after the official announcement this afternoon.

Confused by the ever-growing eReader market? Check the table below for an overview of the devices, their capabilities, and (most importantly), their price.