This is kind of a question without a definite answer, but I'd like to hear some opinions anyway.

So my question is, although GOG games are optimized or corrected to work on Windows 7 and 8, will these games or games made for 7 in mind nowadays struggle to work with future Windows versions like many Win95/98 games do today?

Was it an issue of the software that was used years ago (maybe less standardization) that has cleaned up by now with newer stuff, or will there be a point in time where compatibility breaks again?

This is all assuming no one fixes the game of course.

Shit I never thought of that. I hope so because I like Win 7 and I really don't want to give it up yet. I never forgave Win 7 for taking away Pod Racer and I don't want to lose anything else.

No-one will know until the next versions of Windows are released; i.e. it depends more on Microsoft and whether future versions of Windows do things massively different / drop backwards compatibility.

Nobody can really tell you this... simply because the technology of tomorrow could be vastly different from technology today and it's likely that technology will not be written for compatibility with the past. So save your old PC's and OS's. :P

Hopefully though GOG will be around for the distant future to make these games compatible. That and you always got open source stuff to help fix this... such as DOSBox does for old games today.

I wouldn't expect Windows compatibility to change significantly in the near future. Many features were already overhauled for Vista. Windows 8 made some further changes that affected gaming (Aero is always active, colour depth changes are now virtualised) but those are easily overridden.

GOG are committed to maintaining the compatibility of the games they sell (rather than leaving them in whatever state they were in when first added here) and they have already updated many games to deal with the compatibility changes in Windows 8 and 8.1.

There are only a very small number of games that can't be made to work on a particular version of Windows; everything else will work after making the necessary changes.