When Apple, Inc. (AAPL) introduced the iPad tablet computing device earlier this month, many saw it as immediately being the e-reader device to beat. After all, there were 60,000 e-books in Apple's iBooks store, right? Lest we forget that e-tailer extraordinaire Amazon.com, Inc. (AMZN) released its Kindle e-reader device in 2007 and has over 400,000 books available in the Kindle store for purchase and download. But, with the Apple brand behind it, everyone seems to have forgotten about the Kindle.

It wouldn't reveal the number, but Amazon (AMZN) did announce that it realized record sales for its Kindle e-reader this month. And, there's still the rest of the month to go, including the run-up to Christmas. Just as the battle for e-reader market share began to flare up, it already seems to be over.

This year, Sony (SNE) released a new e-reader, and Barnes & Noble (BKS) entered the market with its Nook device. Both posted early successes, which quickly became problems. The two companies sold out of inventory and won't be able to ship new orders until the new year.

We've all heard of Amazon.com's (NASDAQ: AMZN) Kindle -- perhaps you've even seen it in the flesh. It's portable, well-lit, and comes equipped with wireless technology so a user can download a new novel on the fly.

The competing device, Sony Corp.'s (NYSE: SNE) e-reader ... well, it's portable and well-lit. But if you run out of reading material and you're away from home, too bad. Until now.

Rumors continue to swirl that Sony is not far off from unveiling a wireless version of its Reader. The company's e-reader group has extended an invitation to reporters for a meeting on August 25. Could a wireless announcement be in the offing?

A report today in The Wall Street Journal (subscription required) reveals that Sony Corp. (NYSE: SNE) is set to launch two low-priced e-readers, which could prove to be stiff competition for the wildly popular Kindle devices sold by Amazon.com (NASDAQ: AMZN). Sony's latest entries in the e-reader market, known as the PRS-300 and PRS-600, will be priced at $199 and $299, respectively. By contrast, the cheapest Kindle will run you $299.

Sony's budget-friendlier devices are slated to hit store shelves later this month, with the Journal citing Best Buy (NYSE: BBY) and Wal-Mart Stores (NYSE: WMT) as two retailers planning to offer the e-readers. Meanwhile, the low pricing isn't limited to the gadgets themselves; Sony will also drop the cost of best-selling titles from $11.99 to $9.99, matching the deal offered by Amazon.