Barnes & Noble NookAn update to Barnes & Noble's Nook Color adds Android 2.2, an app store and Adobe Flash, giving people the cheap Android tablet they've always wanted.

Amazon, your move.

The e-reader wars have been quiet ever since Amazon's Kindle won the pricing battle against the Nook e-reader last summer. Neither company has introduced new hardware since then, nor have they dropped prices. (Amazon will soon release Kindle with Special Offers, an ad-subsidized version of the e-reader, for $114.)

But maybe these companies aren't so interested in fighting for dedicated e-reader supremacy anymore. Maybe the color touch screen, reading-oriented tablet is the new battleground for companies like Amazon and Barnes & Noble, who sell cheap hardware in hopes of ensnaring readers in the companies' respective ecosystems.

That's certainly the case with the Nook Color, which sells for a modest $249. The latest software update adds e-mail; Adobe Flash support; and hit apps like Angry Birds, Flight Control, Pulse News, and Quickoffice. Barnes & NoblAmazon Kindlee is building its own app store, with roughly 125 apps now, and more to come.

Now, all eyes are on Amazon to launch a tablet of its own. The company hasn't announced anything, but the signs are all there. Amazon has its own Android app store, along with a market for books, music and movies. It has distribution through its online retail site and partnering brick-and-mortar stores. Rumors are bubbling up, to the point that an Android tablet from Amazon seems inevitable.

If Amazon is indeed building a tablet, I doubt that its hand will be forced by the Nook Color update. But let's all hope that the stage is set for another e-reader price war -- this time, in color.