DigiTimes, a source that is hit and miss when it comes to reports, is reporting that Apple is planning to refresh the MacBook Pro and MacBook Air line of systems in June and will keep the same design as they currently feature. They cite Taiwanese supply chain sources, who reportedly received requests for quotations.
The MacBook Air is said to be switching to a new CPU platform, which likely means Haswell. However, this doesn't jive with the information I've heard about Haswell's release. Haswell is said to be due out in the Q3 of 2013, which is after the reported June refresh. Due to that, I'd take this with a grain of sand, though Apple may hold off shipping the Air until Haswell debuts.
DigiTimes has been hit and miss in the past when it comes to MacBooks, previously predicting there would be a MacBook Air for $799 in Q3 2012. No such device materialized.