Two things:
1- They do have kilometer markers at each K up to 10k. After that, it's every 5k. There's also clocks at the half mark and with 1 mile to go. There's signs after that (1200m, 800, 400, 200?)
2- I think the old school splits would be a cool idea.
3 - Of COURSE the announcing was predictably ... whatever it is. I do not understand how these guys can so consistently have a lack of insight into the race dynamics, competitors, history, etc. considering it's their job to talk about it on TV. If you've ever read the media guide for these things, it's fricking dense and full of information. It's like the LetsRun preview on steroids. It's not like they're calling a horse race - they should refer to it. They should also be waaaay more familiar with the other races out there.
4 -That being said, it's hard to balance the storylines that they want to tell (and that many people want to see) and the running-politics points they want to make with enthusiastic commentary right on the spot. This is a much bigger audience than the Flotrack guys saying, "Oh my God! Solinsky is beating Rupp like the incorrigible child he is!" (Along those lines.) And for some reason, they still don't have a great handle on talking about race and nationality, so they probably err on the side of vanilla commentary a lot of the time. You can only say "Kenyans are good at running" so many ways before you put your foot in your mouth. ("I always pick the one from the more impoverished village down the stretch, Larry.")
5 - Bring back the 1600m.