Today through May 12 (yes, that's Mother's Day), the 7-inch Nook HD is available starting at $149 for the entry-level 8GB model (normally $199) and the 9-inch NOOK HD+ starts at a mere $179 for the 16GB model (normally $269). Both products offer expandable memory via a microSD expansion slot.
The reduced prices are available online at Barnes & Noble bookstores and on nook.com, as well at at retailers including Target and Best Buy.
I suspect that those retailers and Barnes & Noble were sitting on a lot of inventory. However, these prices should help alleviate that problem.
There hasn't been any chatter about Barnes & Noble announcing updates to its hardware, but it could very well have some sort of update -- perhaps only a speed bump -- later this year. Amazon is expected to update its Kindle Fire line in advance of the holiday buying season, if not sooner.
We'll see how Amazon responds to the price drops from Barnes & Noble. A few months ago it lowered the price of its larger Kindle Fire HD 8.9 from $299 to $269, matching the price of the Nook HD+.
Update: Amazon is offering a $20 discount on the Kindle Fire HD through May 12 with the FIRE4MOM code at checkout. That brings its price to $179.