dchuk theorized in a blogpost of his that the purpose is to get people to move over to paid search in order to get this data. I didn't know that the keywords weren't showing up for other analytics software as well. That sucks.
The ssl referrer data still comes in webmaster tools (although almost useless if you are looking for the detail reported in analytics or segmenting on traffic source, etc)
He said only 2.2% of SEOMOZ's searches were affected at the time (the video was made late october 2011). I'm pretty sure by now it's closer to 25% of their searches.
That's what happened to my sites at least. I really thought this was going to affect less than 10% of global searches which is why I didn't really freak out when they first rolled it out. I also thought users would have to go in their search settings to enable it, didn't know Google was going to set this on by default for logged accounts.