Many games use DOS Box version 0.74.2.1. A new version 0.74.3 was released some time ago.

Will the games be updated to use the latest version of DOS Box? Or perhaps the new version has no significant improvements?

Maybe they're waiting for 0.75 which appears to be a work-in-progress "Ideally, 0.75 should have been released by now, but some bugs took a lot longer than expected."?

I presume GOG will not update them unless there is a real reason to do so. Don't try to fix something that works.

However, users can replace DOSbox with their installed games, if they so wish. I recall I once tried a newer DOSBox in e.g. Shattered Steel, to see if it helps with the gameplay problems the game has (had?).

The correct use of the grammatical tense relies on the empiric correlation. Did the new DOSBox version fix the errors the game had? In which case it no longer has them. Otherwise it still does. :)

What new is 0.75 going to bring?

Considering how frustrating it was to play Shattered Steel when it was originally released, I honestly can't see a newer DOSBox magically changing the hitboxes and awful hit detection of the game. :)

Edit: Well, apparently, upgrading DOSBox actually does seem to address some of the hit detection issues. Imagine that.

Improved hardware/DOS emulation, improved compatibility, improved everything...

Would it have the direct3d filters support built in, or will we still be required to use Ykhwong's SVN DAUM builds and the like?

http://source.dosbox.com/dosboxsvn.txt

That goes back to 2010, can we get a cliffnotes?

0.74 WAS released in 2010.

Judging by the release notes, and from my no-knowledge in deep of the work that has been done in the new version, I would say the changelog is not gonna change anything in gameplay as we know. Maybe the OpenGL rendering fixes could improve something, but we have no details either on the work in that area.

I don't think GOG is going to update the games with this brand new version anytime soon, as there's a significant amount of testing and releasing behind it for a (possibly) minor improve if there's improvement at all.