Installed the combo update on 2012 iMac. After a letting it go to sleep and coming back, it woke when I hit a key (Bluetooth keyboard and magic trackpad), but none of the gestures would work, nor key strokes, although MOVEMENT of the mouse pointer was fine (so it wasn't just a connection issue). Clicks wouldn't work. Then after about 10 seconds, all the commands came in at once as it caught up.
I hope this doesn't continue to happen.
You're not alone here. I also installed the combo update on a late 2012 27" iMac. Seemed fine last night during use. Over night the computer went to sleep & this morning when I tried to wake it, for lack of a better term, it bugged out.
I have a Bluetooth keyboard and TrackPad as well as a USB mouse (Razer Naga 2012 for my gaming habits). I woke the machine w/ the keyboard, the screen came on and I tried typing my password into the password dialog but nothing was appearing. I tried a few times to enter the password but nothing was appearing in the dialog, and initially the mouse wasn't visible either but eventually the pointer showed up but I still couldn't click in the password dialog. I should also note that the screen flipped from off to on to off a couple of times, as if toggling the sleep state on its own. No idea WTF that was about.
10 or 15 seconds later, as you said, all the things I did on the keyboard started showing up at once in the password dialog. Very odd.
I did an SMC reset (had already done a PRAM reset yesterday) and will try to reproduce this today. Hopefully I cannot.