I'd say space them out a bit, publishing a lot of content in a short period of time can cause gaps where nothing is published for a long amount of time.

Definitely space them out! Over the summer of 2014 I had a handful of shorts that I could've released at once, but I tried to space them out as much as possible.

And I can attest to what Mighty said, it really helped motivate me to continue brickfilming.

However don't let the urge to produce as much content as possible get in the way of you focusing on making quality animations. Take the time you need to make sure your brickfilms are ready to be released.

My film uploading frequency is pretty simple. I publish them when I'm done. I've yet to have more than one film done at a time. I usually just focus on one idea at a time.

I've never had that problem ever before because I usually make such large films, I'll be lucky if I release two films in the same season.

However, when I first joined BiM soon after releasing my LEGO Pirate epic ("Pirates Rule!") I also wanted to post my older film, but most recent before Pirates', which was Mailbox of Doom.  I didn't want to post them for BiM to see all at the same time, as I thought it would look strange if this newcomer just posted two films at once, so what I did was post my first one, and then wait for a few bits of feedback from BiM, then post my better film the next day.

If you're finishing a lot of stuff around the same time, I'd say just space them out nicely.  Oft times in brickfilming we have times where we can't make much for a while, and filling that gap might be a nice thing.

Currently though, I find it is best usually to work on one thing at a time, and I just work on films that take horribly long but then eventually get done.  I hate to leave everyone waiting, though.