Right, ran into a lot of people last night who were having issues with various things. Consider this a run down to save myself some breath.
So recently the devs pushed an update that compacted the number of patch.mpqs from 9 to 5. Now for some reason the update for some people didn't remove the patches that would now be considered "redundant" (6-9). So if you're running into issues do the following;
*Go to your WoW install
*Locate the DATA folder
*Check it's contents. look to see if you have patch.mpq and patch #'ed 1-5.mpq
*if you have patch6, patch7, etc remove them.
*run wow
While I'm not completely versed in how the file structure works for wow. It's a safe bet from an observational standpoint that the "redundant" mpq files are being read by the client and giving it information and data no longer relevant or data that has changed position in tables due to the mpq squish. HD mods also break things, so if you're running one and some octo content isn't rendering for you (like DDosy). chuck them for now.