For those of you who can't wait for the CK to come out in order to marry a khajiit or a bosmer, there's a little workaround : instead of enabling a khajiit/bosmer NPC to be married, you could change the race of a NPC you can marry to khajiit/bosmer.
Just select the NPC you want to marry and type : "setrace Khajiit" or "setrace Bosmer". The NPC's race will change to the specified one, although they'll retain their voice, dialogue, scripting, etc. - it's just a cosmetic change.
If you're getting awkward results (usually when switching between beast races and non-beast races), try switching to argonian first, then back to the race you want.
I also tried doing the reverse - switching a khajiit to nord to see if their dialogue options for a potential wedding would come up, but to no avail. I'm afraid the voice packages for those races/actors are indeed missing, and that even with the CK, their wedding-related dialogues will be "voice-less". Here's hoping Bethesda still included those voice packages at least for common khajiit/bosmer NPCs, even though they're currently unused in game.