Firmware updates to K-5/K-5 II;
Full video manual control, much like in the K-01. This would also be great if we could get manual control even with the old Pentax M lenses but I understand that can cause issues because the current K mount no longer uses a mechanical link to read the aperture settings on those lenses. Another thing is to be able to change ISO while recording, no other camera has this and it would be an excellent feature.
Video capture at 24/25/30fps, No one would take the camera seriously (video-wise) without these frame rates, due to Europe having 25fps as a standard and USA having 30fps.
Video recording button. Something like using the Fx or RAW button to start video recording or enter video mode.
Crop marks in video mode, which is basically an overlay of lines to show different aspect ratios, a bit like this:
http://images.inosak.org/magiclantern.jpg
Allow an area to be always zoomed in to allow for better MF, much like this:
http://cs6237.userapi.com/u16007354/docs/9254b673a63a/magic_lantern_design1_display1_2.jpg
User select-able bit rates for the MJPEG codec, it currently averages about 70-110mbs which is great for high quality videos! It would be nice if we could go to its max though for the absolute best quality we can get.
HDMI Out to monitor the footage not just playback
Future Video updates;
Hot Pixel removal for stills and video
More frame rates for lower res, such as 120fps+ in VGA mode
Pixel Binning technique to improve video quality (This would also improve iso noise in video mode, the only DSLR I know of that does this is the Canon 5D Mark III)
44.1 or 48khz audio recording
Headphone jack for actually monitoring the audio (The K-01 allows your control Audio gain but there is no way to actually monitor it)
Focus peaking during recording
A few users has shown that they do not like the digital SR in the K-01, and they prefer it without stabilization because of that.
Clean HDMI Out (So we can record footage externally)
Recording to ProRes or RAW(this is a far stretch, it would be an great thing to Cinematographers but we would not be upset or surprised if we did not get this as MJPEG is pretty good)
Waveform monitor
To be honest, everything you could possibly want in terms of control is in the Canon firmware add-on Magic Lantern, so if they were to look at everything that offers they would have a great idea of excellent video control and monitoring.