Apple may release a faster new MacBook Air this month
Based on the report and Apple's previous launch cycles, it seems like this would be a slightly modified version of the current MacBook Air with a faster processor and some new memory and storage options. This isn't likely to be a full redesign.
Last April, for example, Apple released an updated version of the MacBook Air that included newer processors from Intel and lowered its starting price to $899.
Intel officially introduced its line of new Broadwell processors for laptop and desktop computers in early January, so it's possible we'll see new MacBook Airs with these chips in the near future.
Apple is also expected to make some more significant changes to the MacBook Air later this year. The company has been rumored to be working on a 12-inch MacBook Air that has a Retina resolution screen just like its MacBook Pro, but we have yet to hear any official word from Apple.