A couple notes:
A lot of people are using blender to produce content for modern games. Eevee allows the viewport in blender to more closely match the final output in whatever game engine they are using. Having a real time view of your model, as it will look in the final project is invaluable for content creators.
Also, the way that Eevee’s shaders work is much more compatible with Cycles. Though there will definitely be some tweaking to get everything working, the process of transitioning from Cycles to Eevee shaders is fairly painless, and can still leave the Cycles shaders intact. Converting BI materials to Cycles required rebuilding them from the ground up, which took a lot of time. Eevee should be much quicker to transition and adjust to.
Being able to keep both Cycles and Eevee shaders intact makes it easy to use either Eevee or Cycles side by side. As someone who works in previsualization, I know how heartbreaking it is to hear that the client has changed a major feature of the project, and I am already 8 hours deep into rendering the final frames. Having a real-time engine to fall back on to produce high-quality frames almost instantaneously is invaluable.
For animation production, being able to have high-quality playblasts of a test animation is a total plus. Motion graphic artists also benefit greatly, as would a lot of product designers. Interior architecture my rely on the subtle light transfer of a high quality path tracer like cycles for final beauty shots, but having quick previews, or walk through animations that don’t take weeks to render, are totally valuable.
From what I can see, it’s got a lot of positive features that surpass anything BI has to offer, other than legacy support (But I have heard they have some plans for automatic BI + Cycles material conversion on the roadmap). BI is the chopping block for 2.8. I certainly wouldn’t say that Eevee is a replacement for it, it certainly fills a lot of the same needs, and surpasses it in a lot of other ways. Much like I wouldn’t call Eevee a real-time cycles,
From what I can see, it’s got a lot of positive features that surpass anything BI has to offer, other than legacy support (But I have heard they have some plans for automatic BI + Cycles material conversion on the roadmap). BI is the chopping block for 2.8. I certainly wouldn’t say that Eevee is a replacement for it, it certainly fills a lot of the same needs, and surpasses it in a lot of other ways. Much like I wouldn’t call Eevee a real-time Cycles, but it certainly can provide a supporting role and a high quality viewport to assist artists that are using cycles as their engine of choice.
I think it will benefit most blender users once they get used to it. I’ve already been very impressed by its capabilities.