Amazon is preparing a massive overhaul of their Kindle Fire tablet lineup later this year. BGR has it on good authority that at least three new slates are in the pipeline and will be ready to go in time for the holiday buying season.

The first new Kindle Fire is expected to replace the existing 7-inch model which is the company's entry-level device priced at $159. Sources say the new tablet will feature the same screen dimensions but will carry a new panel that will bump the resolution up to 1,280 x 800 pixels. For reference, the existing 7-inch unit uses an IPS display with a resolution of 1,024 x 600.

Sources say Amazon is also planning a brand new version of the 7-inch Kindle Fire HD that will ship with a panel rated for 1,920 x 1,200 pixels, a significant upgrade compared to the 1,280 x 800 pixels found on the current Kindle Fire HD. Like the one it replaces, this tablet will also use the same screen size.

Finally, the Kindle Fire HD 8.9-inch model will see a refresh that bumps the screen resolution up from 1,920 x 1,200 pixels to 2,560 x 1,600 pixels - again, a significant increase. This would give Amazon's slate a higher PPI rating than Apple's iPad as it would pack more pixels into a smaller space.

As for aesthetics, sources say the new Kindle Fire HD tablets will feature a more angular design with a flat slope to the edges instead of the current curved slope. It was described by one source as "chiseled" if that helps at all. Additionally, the power and volume buttons have been relocated to the sloping area on the back of the case to avoid accidental presses. The new slates are said to be lighter than their predecessors as well.

Pricing hasn't been determined as of yet but sources say Amazon would like to keep the same price points as their current lineup. We are told to look for these new Kindle Fire models sometime during the fall, perhaps even as early as September.