I don't think the proposal is a good idea: it adds a trivial inconvenience to posting, and adds more noise to discussion making it harder to find the latest actually open thread. I predict the result would be at least one of: people post in the wrong section, people ignore a number of the categories, or people post less overall.
I'm in favour of more frequent open thread posts, but I think they should remain a single open thread. (Actually if I were making changes I'd probably fold the media recommendation posts into the open threads).
This week's open thread is less than a day old, and has already accumulated more comments than the 15 latest non-open-thread posts combined. I fear the thread will wither and die before Friday.
Going from monthly to weekly open threads was a big hit. Should we ratchet up open thread frequency even more? Should we add more outlets for comments, or will comments inevitably expand to fill the available room?
Proposal for discussion: We follow a regimen of weekly blather threads for the next two weeks, then reassess.
Addendum
I posted a Links on Friday and a Stupid Questions on Monday. In the 5 post-days that they've been up, they've accumulated 32 comments. Based on these numbers, it seems unlikely that these topical open threads will relieve pressure on the main Open Thread and so I've stopped the experiment.