Don,
You are right about Adobe making the DNG file (2006). This means it is just 4 years old, so we're not thinking about dicontinuation quite yet. Give it a few decades and it will be replaced, or someone will invent a format that is so good that all the camera makers will use it (currently every manufacturer has their own RAW format--annoying because you need proprietary software to process it).
Kodachrome was around as a format for decades--loads of photogs used it. It has now been discontinued in favour of Ektar. However, the digital world moves much faster, so I wouldn't be surprised if in 10-20 years time we have a whole new format and all that entails: converting with proprietary software, reburning discs, re-archiving etc.
Regarding resolution, as you say it depends on a whole lot of factors. Certainly the difference is pretty minimal, as you said. Saturation, dynamic range (how they handle very bright areas for instance) may leave the better films like Velvia 50 with a slight edge, but again it depends on a whole load of things.
The biggest advantage comes in logistics, reliability and equipment:
--Like I said before developed film is very durable and can be viewed anytime with the latest scanners.
--No time spent messing around the computer (I'm on it long enough as it is)
--Lovely, cheap manual cameras an optics (personal preference, but I love how an old camera gives you access to important things quickly without piling on unnecessary features that will just distract me).
Ken Rockwell has a great article on the subject:
http://www.kenrockwell.com/tech/why-we-love-film.htm