ArsTechnica reports that hidden amongst all the announcements at the Intel Developer Forum was a brief mention that Intel had introduced "the company's second-generation dual-core mobile processors for increasingly popular ultra thin and light notebook PCs."
These new processors represent the Penryn update to the custom processor that is used in the MacBook Air.
Both the SL9400 (1.8GHz) and the SL9300 (1.6GHz) use a 1066MHz FSB and carry 6MB of L2 cache. Intel is also introducing a pair of 10W processors: the SU9400 (1.4GHz) and SU9300 (1.2GHz). Both of these chips run on an 800MHz FSB and carry 3MB of L2 cache.
These new processors will be available to all manufacturers and not just Apple. Readers may recall that the original MacBook Air processor was a custom configuration designed for Apple by Intel.
The new processors are expected to be available in September. Apple has been recently rumored to be prepping a MacBook Air update which could use these new processors.