New MacBook Airs are due any day now, and the rumor mill is flying off the handle. The latest rumor suggests that Apple may use new and much faster 400Mbps NAND flash storage chips that will be soldered directly to the motherboard.

The new technology is called Toggle DDR 2.0, is an industry first, and sports 64-gigabit chips manufactured using a 20NM process – the result is a decrease in size and an impressive maximum data transfer rate of 400Mbps – nearly double that of the current blade SSDs.

While solid state storage is certainly a good thing in terms of performance, and while it’s important to decrease the size and footprint of hardware as much as possible, I cringe a bit at the thought of soldering storage onto the motherboard. What about upgrading your storage space in the future? What if your SSD fails?

Currently, Apple’s “blade” SSDs in the current MacBook Airs seem to serve the purpose well, and can be produced and upgraded by 3rd parties – would the lack of upgradable or easily replaceable storage have a significant impact on the MacBook Air?

In addition to the possible new type of SSD, the new MacBook Airs are expected to include new Ultra-Low Voltage Sandy Bridge processors, and Intel and Apple’s new Thunderbolt technology. They’re also expected to come pre-installed with OS X Lion, and are expected to arrive sometime this month, possible on July 14 alongside the release of OS X Lion.

The trade off of the new soldered-on SSD would be gains in speed and decreases in the space that the flash memory would take up. This is just a rumor, so don’t take it too seriously…but what are your thoughts? For me, this would be bordering on “deal-breaker” status.