The Raspberry Pi was intended as a learning device. David Braben, previously known for Rollercoaster Tycoon and other video games, noticed that computer science education was lacking and he wanted to contribute to its advancement with a cheap, portable, and highly-programmable PC. Yesterday, the organization announced a new model, the Raspberry Pi A+, which is (theoretically) cheaper, smaller, and has a few better components. This announcement follows the release of the Raspberry Pi B+ from last July.
I say “theoretically cheaper” because, although the organization is touting a price reduction from $25 to $20 USD, that always depends on the reseller. MCM Electronics, one of the foundation's US-based distributors, is selling the A+ for its list price of $20 (plus an extra ~$10 in shipping, before tax). In the UK, however, the currency conversion works out to about $25 before VAT. That said, the UK is known to be expensive for electronics.
Whatever the price, the device is slightly improved. While it keeps the same, Broadcom BCM2835 SoC and RAM, the memory has been upgraded to a locking MicroSD card slot, the audio's power delivery has been improved to reduce noise, and the number of GPIO pins has been increased from 26 to 40. The latter enhancement will allow the Pi to interface with more, and different, sensors and motors for robotics and other embedded applications.
The Raspberry Pi A+ and B+ are both currently on backorder for $20 and $35, respectively, before a $10 shipping fee and any applicable taxes.