It will probably run a lot worse. At least on launch. I expect a lot of bugs, some performance issues and a very unpleasant experience on ED forums.
Then, it will be gradually patched into something that actually works, and after that, my take is that it will need a little more resources than today, but not radically so.
I think that it will run a little bit worse, but nothing that will change the overall experience. The problem with this statement is that I consider the experience today to be pretty bad in that regard. For those who have top of the line machines it will run alright, not great, and for those with average or even above average machines it will continue to be borderline acceptable.
That said, I’m very optimistic overall about their roadmap. I think they are actually addressing everything the users asked them about. Weather is going to make DCS a different experience altogether and all the improvements, although will take a long time to actually arrive, will keep it current and relevant.
I have high hopes for Vulkan, even when thinking that, realistically, we cannot expect a lot more than 10% improvements for their first implementation. In the long run, I think we will get a lot more headroom for ongoing enhancements.
But I’m thinking it will get worse before it gets better…