MBA - unlikely. The current iPad retina display consumes 7W/h. The MBA line, known for portability, will not add a much bigger battery to accommodate this. iMac - impossible. 4k displays are still over $10k. MBP - Apple can announce the death of the optical drive and use that space for battery, thus keeping the thin form factor. Retina display will make the MBP truly a "pro" machine again and pull it farther away from the MBA. You want ultraportability, buy the MBA. You want retina display and better GPU, buy the MBP. They will probably release it 2013.