I think it will come later this year.
I'm hoping for a quad-core A9X at 1.8Ghz, 4GB ram, 12 hour battery life, 11" 300 ppi display that can be color calibrated, pressure sensitivity for drawing, split screen multitasking and sizes that come in 64, 128 and 256GB for $799, $899, and $999.
What we'll probably get: tri-core A9X at 1.6Ghz, 2GB ram, 12 hour battery life, 12" 240-ish ppi display with no calibration which makes it less useful for designers and photographers and sizes that come in 32, 64 and 128GB for $699, $799, and $899. Pressure sensitivity is up in the airmakes sense for a pro device but we'll probably just get split screen multitasking.
I also hope Apple releases their own keyboard smart cover/case, and some ability to do gestures such as scrolling and switching apps with a magic trackpad type input bar.