Here's what I've done to stop my quick/autosaves from being restored.

1) Disable Steamcloud globally. Steam>Settings>Downloads & Cloud (can't say for sure that this makes a difference)
2) Browse to your Steam userdata folder, find the "remote" folder that contains both your quick and autosave.fos files. Delete these.
3) Start New Vegas and make sure that nothing has been restored.
4) Stick to manual saves anyway, just in case, and back these up with the occasional alt-tab.

I haven't verified that this works for extended periods of time yet, but I will be trying it out today.

After deleting the contents of that folder, your next quicksave and autosave will backup there, and all future quicksaves and autosaves will revert to those ones when you restart the game. You can deny write access to that folder after you delete its contents (instructions have been detailed in several of the save bug threads), to prevent any files from getting in there. That seems to permanently prevent save file reversion.

This isn't my experience at all. After disabling Steamcloud and playing, I don't see quick/autosaves turning up in this folder again.

I wasn't having the bug on Tuesday (tested it extensively), but it showed up for me on Wednesday. I had Steam Cloud turned off for the game and globally for Steam, but that didn't seem to make any difference. I'm not sure what changed, unless it was related to Steam turning off Steam Cloud functionality on Tuesday while they were trying to fix the problem.

Last night (both before and after the patch), I could not get any quicksaves or autosaves to persist from one session to the next. Denying write-access was the only thing that prevented files from getting back into that folder. If you're not seeing the save reversion problem then that's great for you, but I would keep an eye on it and not get too comfortable relying on Quicksaves--at least do a manual save before ending your gaming session.